Tag Archives: Top-Grade Ammo

RELOADERS CORNER: Cartridge Cases: The Outside, Part 1

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Lubrication is absolute essential in the reloading process, Here are a few ideas on which and how. READ MORE

lubing cases

Glen Zediker

What’s the most important thing in case resizing? Case lube! Overlook it or under-do it once and you’ll know why! A stuck-case remover is one of my very least favorite tools…

I have long used and recommended petroleum-based case lubes. More: I prefer those that are applied by hand, literally with the fingers, because I think it’s a better assurance that the right amount, to all the right places, will get laid down. I will quickly concede, though, that they are messy and slower than other methods.

imperial case lube
This is my favorite case lube. I took advice from Sgt. Norris after complaining how hard it was to get a good sizing pass on a Lake City .308. Sure enough. This made it easy. Been using it ever since. It’s not really wax. Use it like shoe polish: rub a little on your fingers and then rub it onto the case with a “gimme money” motion.

Spray-on-type lubes are very often used and recommended, especially by high-volume loaders because a good many cases can be treated and then even stored before use, so say the claims. I strongly suggest taking steps to prevent the lube from finding its way inside the case. A thin piece of cardboard placed atop the standing cases works well for this. There’s worry otherwise that the lube might affect the propellant. That does depend on the formulation, but I prefer the “no-chance” approach. I’m a “slow-down” sort of loader. That doesn’t mean I don’t want to save time or be as efficient as I can be, but I’ve just not found the speed advantage to spray-ons to overcome their performance. Sprays are not quite as “slick” as rub-ons.

Lanolin-based and wax-based alternatives also have their following. As do water-based lubes. The wax lubes indeed work and also clean up (off) easily, as does lanolin. I’ve not been a follower, though, because I find many to be more difficult to apply evenly and, one more time, just not quite as slick at petro-based products. Some of the wax-based lubes also make claim to “apply-now, use later.” I’m not sure what the appeal of that is, but there it is for those it appeals to. There are also a number of “proprietary” formulations out there now. I have not tried them all.

hornady case lube
Hornady pretty well has it covered: one for every opinion! Try them all! But I will wager you’ll like petro best… That’s the one in the bottle. Hornady claims their spray lube doesn’t contaminate powder, and that makes it applying it more straightforward.

A tip I picked up umpteen years ago by the man who got me started loading was to get an ink stamp pad (office-supply store variety) to apply roll-on type lubes. Indeed, that works way better than the industry pads I’ve tried.

Back to petroleum lubes: aside from providing smoother feel in sizing, which I have to believe also indicates “better” lubrication qualities, these don’t build up as much within tooling. I take apart my sizing die every now and again and swab it out, like I would a rifle chamber.

For best results, no matter which lube type you’re using, an even (thin) coating gives best results. With a good petro lube, it doesn’t take much. If you see any denting (usually in the case shoulder area), that resulted from hydraulic pressure and is a sign there was too much lube (too thick a coat). No worries, though: shoot the case and they’ll iron back out. Just use less lube next time!

Lubing the case neck inside is debated, but I favor it. However! Only very sparingly! That is why I really like the finger-applied lubes: just a little “wipe” across the case mouth eliminates the “gaunch” noice from the expander. I don’t use the graphite-applicators (the bin-and-brush types) because I haven’t noticed a whopping lot of difference in neck sizing with or without it.

forster lube
For best sizing results, I prefer the “rub-on” lubes. This one is from Forster. Never any worries about too much, too little, or complete coverage.

And, by the way, lube a case each pass through the die. This is important when setting up a sizing die where you might make a few passes with the same case. Don’t risk it! Stuck cases are total mood killer.

Clean the lube off the cases! There will be some now who will just roll their eyes, but I use denatured alcohol and a bath towel pour some on the towel, but the cases on the towel, fold the towel over the cases, and roll them around. Fast and simple! That works for petro-based. Others need more attention: just rub it away, or use detergent.

I do not recommend using a tumbler-type cleaner on loaded ammo!

Sho, there is a (slight) chance that a bullet tip might detonate a primer, but that’s not why. Why is because the propellant gets pulverized, and that, no doubt, will change its burn characteristic.

case cleanup
This is what I use to clean loaded rounds, along with the towel it’s sitting on. Lay out the towel, put down the rounds, pour some alcohol, fold the towel over the cases, and roll them around. Then hang the towel to dry for another use. Zero residue.

The reason to clean off the lube is because it lubricates, and that’s a bad thing on a live round. The case is supposed to stick tightly to the chamber when it expands under pressure. Any slip increases bolt thrust. I once saw a fellow douse a loaded 30-round magazineright down the middle with WD-40, to “make sure the bullets fed…” NO NO NO. Oil on a cartridge doubles bolt thrust!

Case lube is not a case cleaner!

Make sure the cases are clean prior to sizing. They don’t have to gleam, just be free from dirt and gritty dust. If you’re seeing a applicator pad, for instance, getting a dirty spot on it, well there’s your clue.

We’ll talk about that next time.

 Check out the selection from Midsouth HERE

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Primer Tech

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It may be the single-most influential reloading component, so learn all about it: the primer! READ MORE

rifle primer

Glen Zediker

This is one component in the collection that might not get all the attention it warrants. That’s because it is the one thing, above all other components, that you don’t want to just swap and switch around.

We’ve all heard cautions about testing new lots of every component, especially propellant, but primers not only change lot to lot, they vary greatly in their influence on any one load, brand to brand. The difference in one brand to the next can equal a good deal more or less pressure, for instance. While there are “general” tendencies respecting the “power” of various-brand primers, always (always) reduce the load (propellant quantity) when switching primers.

This has become more of an issue over the past few years as we’ve faced component shortages. I can tell you without a doubt that going from a WW to a CCI, or from a Remington to a Federal, can have a major influence on a load. I establish that from chronograph readings. No doubt, it’s best to have a good supply of one primer brand and lot that produces good results, and when that’s not possible, it’s a hard sell to convince someone to stop loading ammo and get back to testing. But. It is important. I can tell you that from (bad) experience. How I, and we all, learn most things…

When I switch primers, whether as a test or a necessity, I reduce my load ONE FULL GRAIN. There can be that much effect.

The Thing Itself
A primer is made up of a brass cup filled with explosive compound (lead styphate). Lead styphate detonates on impact. Primers don’t burn – they explode! In the manufacturing process, this compound starts as a liquid. After it’s laid into the cup, and while it’s still wet, a triangular piece or metal (the “anvil”) is set in. When the cup surface is struck by the firing pin, the center collapses, squeezing the explosive compound between the interior of the cup and the anvil. That ignites the compound and sends a flame through the case flash hole, which in turn lights up the propellant.

Primers are dangerous!

Don’t underestimate that. I’ve had one experience that fortunately only created a huge start, but I know others who have had bigger more startling mishaps. These (almost always) come from primer reservoirs, like fill-tubes. Pay close attention when charging up a tube and make sure all the primers are facing the right way, and that you’re not trying to put in “one more” when it’s full! That’s when “it” usually happens. What will happen, by the way, is akin to a small grenade. Static electricity has also been blamed, so keep that in mind.

primer tray
Take care in filling primer tubes! Make double-sure all are facing correctly, and a good primer tray helps. This photo shows the correct orientation for using primers one at a time. To fill a primer tube, make sure the “shiny side” is facing up! Flip the tray over.

Sizes and Types
Primers come in two sizes and four types. “Large” and “small”: for example, .223 Rem. takes small, .308 Win. takes large. Then there are pistol and rifle in each size.

Rifle primers and pistol primers are not the same, even though they share common diameters! Rifle primers should have a tougher cup, and, usually, a hotter flash. Never swap rifle for pistol. Now, some practical-style competitive pistol shooters using their very high-pressure loads (like .38 Super Comp) sometimes substitute rifle primers because they’ll “handle” more pressure, but they’ve also tricked up striker power. That’s a specialized need.

Further, some primer brands are available with a “magnum” option. Some aren’t. My experience has been that depends on the “level” of their standard primer. A magnum primer, as you might guess, has a more intense, stouter flash that travels more “deeply” to ignite the larger and more dense powder column. It reaches further, faster.

large rifle primers

large rifle magnum primers

There’s no real reason not to experiment with “hotter” and “colder” primers, whether the case is stamped “mag” or not. Keep in mind that the experiment is all about the initial flash effect. And keep in mind that this (without a doubt) demands a reduction in the propellant charge at the start.

Over a many years I’ve seen some tendencies respecting flash effect. Using routine cartridges, like .308 Win., single-base extruded propellants tend to shoot well with a cooler spark to start, and the double-base, especially spherical-types, seem to respond best to a hotter flash. Many seem to think that the coating (necessary to form the spherical) and the inherent greater density (less air space between granules) in a spherical demands a little faster start.

Flash consistency is very important, shot to shot. The consistency of every component is important: bullet weights, diameters, case wall thicknesses, and all the way down the list. We’re hoping to get more consistent behavior from a “match” or “benchrest” primer, and we’re paying more for it. I can tell you that some brands that aren’t touted as “match” are already consistent. That all comes from experience: try different primers, just respect the need to initially reduce the load each test. I can also tell you that my notes tell me that the primer has a whopping lot to do with how high or low my velocity deviations plot out.

One last: there are small variations in primer dimensions (heights, diameters) among various brands. These variations are not influential to performance. But! Small diameter variations can influence feeding through priming tools. This can be a hitch especially in some progressive loading machines. Manufacturers usually offer insight (aka: “warnings”) as to which are or aren’t compatible, so find out.

Check out Midsouth products HERE
Primer trays HERE

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: 4 (More) Semi-Auto Details

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Beyond precision and accuracy, the base goal for any handload is safety: follow these recommendations to ensure yours! KEEP READING

Glen Zediker

Since I sincerely think it’s important to know what you’re up against, in one way of looking at it, when you load for a semi-automatic rifle, there’s more this time. I don’t mean to say “up against” like it’s some sort of adversarial relationship, a fight, but not respecting some of these points can create problems.

The gas port pressure issue was addressed last time, and it’s one of the most influential. Not only does too much port pressure create excessive action cycling, it also shortens case life. The cases take a bigger beating, more expansion mostly, when the bolt tries to unlock too quickly. Clearly, I’m back to using the AR15 as the central example, but virtually all semis succumb to the same set of behaviors (yes, including the gas-piston guns).

nosler brass
My current choice in a go-to for my “better” AR15 brass is Nosler. It’s not exactly thin but it is tough, and, by my experience, holds up to my standard. It’s also ready to load (well prepped).

One: tough brass
Therefore, next on the list is choosing a tough case! Tough, here, means “hard.” Brass is an alloy and the makeup varies from maker to maker.

The reason that a harder composition helps is because it’s more resistant to expansion, not as elastic. That might sound, on the front end, like a bad thing because harder brass is also more brittle so could tend to succumb easier to the ills of excessive expansion. Softer brass will conform more agreeably. True. It might seem like an equitable trade off, but I assure you that it is hardness ultimately that matters most. I notice the softness mostly in primer pocket expansion, or I should say that harder cases don’t open up as quickly.

Thicker cases, by the way, are not necessarily harder. Again, that’s in the alloy composition itself. Some high-dollar cases, Lapua for instance, are relatively soft despite being thick-walled.

The overall best choice for reuse in a semi-auto is probably good old Lake City. It’s exactly what it should be, and that’s been pretty well proven for decades. LC is easily available but, except in rare circumstances, will be once-fired. Most cases left over from commercially-available NATO-spec loadings are likewise fine. Lake City, as a bonus, also tends to be relatively thinner-walled (higher capacity) than many of the commercial brands, and its quality (wall thickness) is pretty dang good.

Check out what Midsouth has HERE

 

Two: adequate case shoulder set-back
Next, and this is a huge source of debate and disagreement amongst my readers, but, since now I’m strictly speaking of semi-auto needs I doubt there will be much dissent: full-length resize all cases! It’s a matter of degrees, and getting handle on port pressure (plus) taming down an excessively functioning gas system, reduces this difference: but most cases from most semi-autos will emerge with a pretty well-blown case shoulder. Make double-sure you’re sizing the cases down to at least 0.003 clearance. There are gages that help, and HERE is a link to one.

If you don’t there are safety and function problems ahead.

Three: adequate case neck “tension”
Likewise, make double-sure the case neck is being reduced an adequate amount to retain the bullet. There should be a minimum net difference of 0.003 inches between sized outside case neck diameter and loaded round outside case neck diameter. Reason: don’t take a chance of inadvertent bullet movement during the recoil and feeding cycles. That movement can be back or forward! It’s easily possible for a bullet to jump ahead when the inertia from the bolt carrier assembly chambers the next round.

sized case neck
Same as said about headspace: a bolt-action can “get away” with a lot, but a semi-auto round has to be constructed with an eye on cycling stresses. A firmly-held bullet resists stubs and intertia-induced movement. I recommend a minimum of 0.003 “grip.”

Four: tough primer!
Choose a tough primer! There’s a floating firing pin on an AR15 (M1A also) that is supposed to be held in check but that system doesn’t always work! If you load and extract a round and see a little dimple in the primer, that’s from the firing pin tapping off of it (again, created by inertia of bolt closing). A combination of a high primer and a sensitive primer cup assembly can create a “slam-fire,” which you do not want.

primer indentation
This always scares me. A tough-skinned primer is a very wise choice loading for anything with a floating firing pin, like an AR15 or AR10.
No! Check each and every primer to make sure it’s seated to below flush with the case head!

Brands? CCI has some mil-spec primers that work well, and I’ve had great success with Remington 7-1/2. Some of the well-respected “match” primers are a little thin. The CCI and Remington also hold up well to the (sometimes) greater firing forces working on the primer (again, from the quick unlocking).

And, finally, make double-sure that each and every primer is seated to below flush with the case head! That’s true for any firearm (because it also means that the primer is fully seated) but imperative for safety in a semi-auto. This is especially an issue for those who use a progressive-type loading press. There’s nothing wrong with the press but it may not give the sensitivity in feedback to know that the primer is fully seated without checking.

Here’s what I use from Midsouth

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Gas Port Pressure

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It’s not always possible to separate guns from loads, and there are some important things to know to get the most from your semi-auto. Here’s one! KEEP READING

casing in air

Glen Zediker

I have spent the last couple of segments taking a big step back recollecting my own (early) experiences and education as a handloader. Hope you’re happily indulging me, and hope even more that there’s been some good ideas that have come from it.

I started reloading as a matter of economy, and because I wanted to shoot more. Said then and said again now: if the impetus for reloading is saving money, you really don’t save money! You just get to shoot more for the same cost. Hope that makes sense, and likely you already understand that. Clearly, there are other reasons or focuses that attract folks to handloading, and personalizing ammo performance, improving accuracy, are leading reasons.

I’ve been at least a tad amount (to a lot) biased all along in my department topics toward loading for semi-automatic rifles. That’s been done for a few reasons, and the primary one is that, no question at all, there are specific and important details, a lot of dos and don’ts, in recycling ammo for a self-loader.

This is the reason I’ve been careful to specifically point out the “semi-auto” aspect of any tooling or preparation step. I’d like some feedback from you all with respect to your motivations and applications in handloading. Why do you do it?

Another reason is that, and I know this from much input, as happened with me 45 years ago, my interest in learning to reload came with ownership of a semi-auto that I absolutely loved to shoot! Here of late, my plumber, for a good instance, proudly announced to me outside the local hardware store that he had just purchased his first AR15 and showed me the paper bag full of .223 Rem. cartridges he had just purchased there. A scant few weeks later: “Could you help me get together some tools and show me how to reload?” I did.

Back to the focus, finally (I know) of this topic: what are those differences comparing semi-autos to anything else?

There are a few points, but one of the first, and one of the most important, is component selection. Case, primer, propellant. Propellant first.

AR15 gas port
As .224-caliber bullets get heavier, there’s a tendency toward many using slower-burning propellants. Often, the slower-burning fuels produce lower chamber pressures, which means more velocity potential (that’s true with just about any rifle cartridge). But! Gas port pressure will increase with slower and slower burning propellants. Can’t have it all, and make sure “function” is first on the list. That’s safe and sane function, by the way, not “over-function!”

I’ll assume, pretty safely, that the semi-auto we’re loading up for is an AR15, or some take on that platform. If so, it will have a “direct impingement” gas system. That’s a pretty simple arrangement whereby the gas pressure needed to operate the system, which cycles the action, is bled off from the barrel bore via a port. From there it goes through a manifold and then into a tube, and then back into the bolt carrier via the bolt carrier key. Gas piston operation is more complex, but what’s said here applies there also respecting propellant selection.

So, it’s kind of a wave. The idea is to get the wave to peak at a point where there’s not excessive gas entering the system, but there is sufficient gas entering the system. Mil-spec. 20-inch AR15 calls for 12,500 psi, for what that’s worth. And “piston” guns are nowhere near immune from concerns about port pressure.

The burning rate of the propellant influences the level of gas pressure at the gas port, and this, easy to understand, is referred to as “port pressure.” The original AR15 rifle gas system component specs (20-inch barrel, port located at 12 inches down the barrel) were created to function just fine and dandy with 12,000 PSI port pressure. Much less than that and there might not be enough soon enough to reliably cycle the works. Much more than that and the operating cycle is accelerated.

Port pressure and chamber pressure are totally separate concerns and only related indirectly.

Rule: slower-burning propellants produce more port pressure than faster-burning propellants. As always, “faster” and “slower” are relative rankings within a variety of suitable choices. The answer to why slower-burning propellants produce higher pressure at the gas port comes with understanding a “pressure-time curve.” A PT curve is a way to chart consumption of propellant, which is producing gas, along with the bullet’s progress down the bore. It’s what pressure, at which point. I think of it as a wave that’s building, cresting, and then dissipating. Slower propellants peak farther down the bore, nearer the gas port. Heavier bullets, regardless of propellant used, also produce higher port pressures because they’re moving slower, allowing for a greater build-up about the time the port is passed.

RE15
I put the (very safe) cut-off at H4895 burning rate. I’ll go as slow as RE15, and have with safe success, but its influential differences are noticeable. I can tell you that a 4895 is well within the optimum range to deliver intended port pressure (“a” 4895, mil-contract variety, was actually the early original 5.56 propellant).

To really get a handle on all this you have to picture what’s happening as a bullet goes through the barrel in a semi-auto, and keep (always) in mind just how quickly it’s all happening. Milliseconds, less than a few of them, define “too much” or “not enough.” As the bullet passes the gas port, there’s still pressure building behind it, and there’s more pressure building still with a slower propellant. After the bullet exits the muzzle, the pressure doesn’t just instantly go away. There’s pressure latent in the system (all contained in the gas tube and bolt carrier) that’s operating the action.

The symptoms of excessive port pressure come from the consequence of a harder hit delivered too soon, and what amounts to too much daggone gas getting into and through the “back,” the bolt carrier: the action starts to operate too quickly. The case is still a little bit expanded (under pressure) when the bolt starts to unlock and the extractor tugs on the case rim, plus, the increased rush of gas simply cycles the action too quickly. That creates extraction problems and essentially beats up cases. They’ll often show bent rims, excessively blown case shoulders, stretching, and so on.

Getting gas port pressure under control makes for improved function, better spent case condition, and less wear and stress on the gun hisseff.

There’s a huge amount more to talk about on this whole topic, and a good number of ways to get everything working as it should. But. For this, the most a handloader can do, and it’s honestly just about the most influential help, is to stay on the faster side of suitable propellants. Without any doubt at all, there will be rampant disagreement with my advice: no slower than Hodgdon 4895. Most all published data lists propellants from faster to slower, so find H4895 and don’t go below it. That’s conservative, and there are a lot of very high scores shot in NRA High Power Rifle with VARGET and RE-15, but those are edgy, in my experience, and define the very upper (slowness) limit.

m14 gas system
This doesn’t only apply to AR15s. The M1A is VERY sensitive to port pressure, which is also propellant burn rate. It’s a gas-piston gun. Same cut-off on burning rate is advised for these: H4895. I sho learned this the hard way by dang near wrecking my first M1A: bolt stuck back after firing a dose of H4350. That was before I met Sgt. Jim Norris and got the lecture I’me giving you. Thanks Sarge!

That alone doesn’t mean all AR15 architectures will be tamed (carbine-length systems are particularly over-zealous), but it does mean that port pressure will stay lower, an important step.

A caution always about factory ammo: some is loaded for use in bolt-actions (especially hunting ammo(, and might bea very bad choice for your .308 Win. semi-auto. AR15s are actually fairly more flexible in showing clear symptoms, some no doubt due to the buffered operating system and overall mild nature of the .223 Rem. cartridge.

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

 

RELOADERS CORNER: Blissful Moderation

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Glen Zediker recollects and reflects on the first advice he ever got on choosing a load: all things in moderation, pressure and velocity included! READ IT ALL

range load
When you just want to load up and go have a go at the range, there’s no need for speed. But! There is a need for enough pressure-power for reliable, clean function. I suggest trying something in the “medium” range for daily use. Your rifle, your barrel, your cases, and your senses will all thank you for reducing the shock by taking “two steps to the left” to find a load. Promise: you will not notice anything at all negative from any lack of “power.”

Glen Zediker

I spend a great amount of space in this department warning, and I hope educating, on the signs, signals, dangers of excessive cartridge pressure. That’s all been and being done because, for the majority, maximizing velocity is an ammo-goal. Hunters, varmint and game, competitive longer-range shooters, usually want the most they can get from bullet flight performance, and also impact strength.

For me, there’s zero doubt that more speed is a better score on a full-length NRA High Power Rifle course. (Side note: it is a fallacy that lighter loads are more accurate. They’re not, or not because they’re lighter. Some of the best perforations I’ve seen are with maxed loads.)

But! I shoot a toned-down load for reduced-distance courses (as well as for the 200-yard events on full-length), and my general-purpose clods-and-cans load is a lower-stress recipe.

I mentioned last time that I had recently fired a good deal of current NATO-spec ammo and was, I guess “impressed” is the right word, with its power level. The stuff I make up for afternoon fun-runs is a good deal less stressed.

I’m not at all recommending a “light” load. Just let’s call it a solid “medium.” Looking over my notes for the past umpteen years, going through my last most current load-data notebook, I saw what was to me an interesting happenstance. I tended to be pretty much right at one-and-one-half grain less than maximum (and about two grains with .308-class rounds).

dirty case
Signs of a load that’s too “light” include, clearly, one that won’t cycle the action reliably on a semi-auto. Another couple, for any action type, include an unusually dirty chamber and sooted-up cartridge case necks and shoulders. A little lighter still and you might see a primer that’s backed out a tad. Those all result from the case not expanding fully to seal the chamber forward and stretch to comply closer to chamber dimensions end to end. A little reduction won’t normally show any of this, and, tip: go a tad toward the faster end of suitable burning rate for general use.

Thats not a light load! It’s “three halves,” three one-half grain drops. That half-grain, and some might recollect my mentioning this a few times in the past, is my always-recommended “come-off” step for any pressure sign (not a tenth or two, but a “full” half grain). Any other over-pressure indicator from that point then signals need to come off another “full” half-grain. So I pretty much come off those two halves from the get go, add another, and, guess what? Never nary a pressure concern.

Slightly faster-burning propellants, in my experience, lend themselves better to the “medium” power level reduction in terms of maintaining accuracy. As always, “faster” and “slower” are values within a small range of propellant rates suitable for a particular cartridge and bullet. And, in following this plan, when needed bump it up to full speed with predicatable results.

For .223 Rem.-class cartridges, a half-grain is worth ballpark 40-50 feet per second, again depending on propellant.

The advantages of a “medium” load are predictable, but here’s my list: plain old easier on the gun, and on the barrel, and on the self. Again (and again) I’m not talking abut a “light” load, just one that’s maybe 95-percent, a solid 150-200 feet per second less than published maximum. Case stress will be reduced, and that’s associated with length trimming frequency and overall “life” before primer pocket enlargement and general stretch-thinning, cracking symptoms retire the brass.

Back to my “story,” which was the interesting happenstance (all this was all brought back to me by the initial outing with my new old AR15 I talked about last edition, and my 16-year-old son asking me if I could teach him how to reload because we ran out of ammo so quickly…): So. When I first learned to reload I was 15. This event coincided with my first AR15 rifle, which was purchased new at a Skaggs drugstore. Right. My mother did not eagerly agree to sponsor a reloading setup, but, being a wise-enough woman, did interpret the math the same way I did: I could shoot a lot more for a lot less if I was doing my own. So, I had a friend, Gary. Most fortunate man to know. Gary, and I see this more clearly each year that passes, knew more about guns and shooting than any 10 people I have since encountered.

We went to Bald Bob’s Sporting Goods in Rifle, Colorado. He chose an RCBS kit for me, a piece at a time. Bob sold RCBS only. Press, dies, scale, meter, case lube, doo-dads, and, of course some propellant and brass and bullets and primers. And a Sierra Bullets loading book. So, back home, and a short time later, there I sat before my new array of green pride-and-joys. After stern lectures about things I was never supposed to do, and at least an equal number of things I was always supposed to do, we got this show flowing downriver.

Gary had chosen IMR 4198 for me for a propellant. He said it was clean-burning and economical. Didn’t take much of it. I had some Speer 55-grain full-metal-jacket bullets, some Remington cases to go along with the empties I had saved in a paper bag, and some CCI primers. Now. We looked at the loading tables in the Sierra Manual, and he had me find my cartridge and bullet. (He already knew exactly where we were going, so this was for my benefit.) He pointed out the “maximum” load and the “starting” load, one on the far right and the other on the origin point of the table on the left. He then counted back two places from the far right: 20.5gr. He said, “There. That’s the one. It’s not going to give you any troubles, and it’s adequate for function.”

“That was easy,” I thought.

I have since learned that advice was too good not to share.

If you’re looking for a good load, and you know the propellant is wisely-chosen, going two steps down from the manual-listed maximum should, indeed, be a great place to start, or to stay if you are sans chronograph. Time after time, I have noticed over the many, many years I have now been doing all this, that the “two steps back from max” procedure is safe, sane, and satisfying.

reduced load list
Here’s a page (“the page”) from my now-ancient Sierra manual. Not all manuals agree (not nearly) on max loads, and not all are done in multiple increments, but the essential advice is reducing the max load by two steps, or about one-and-one-half grains of propellant in this case (reduction amounts vary, certainly, based on the cartridge). It’s wise advice from a wise man, and I’m talking about Buddy Gary. I just pass it along because it sho works for me!

I shot about a gozillion rounds of 20.5 grains of 4198 through that SP1. Since it was not a max load, I could also change the bullets without worry, going from one brand to the next at the same weight, of course. I could change cases and even primers. It was a tenth shy of one-and-one-half grains under maximum. I don’t recollect ever grouping that rifle on a paper target. I zeroed it based on preference and I also don’t recollect ever missing anything I aimed at by more than a little bit, and never twice.

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: 5.56 NATO: “GO,” “NO-GO”

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This “warning” has been around, and around, for years, but it’s still not always heeded, or understood. Read why and how it matters HERE.

nato stamp
The circle-cross stamp is a NATO-spec cartridge. Your barrel might be marked “5.56” or a more lengthy disclosure referencing its specs. If it’s “.223 Rem.” do not fire a NATO round through it! Your barrel might also not be marked at all. I’ve increasingly seen that. Get it checked. A NATO round will chamber perfectly in a .223 Rem. All exterior dimensions are patently the same, again, it’s the pressure level.

Glen Zediker

I know this is “Reloaders Corner,” but, every now and again at least, I rip open the end of a cardboard factory cartridge box, or five.

I just got finished building up a “retro” AR15 for a new book. Reasons for that are a few, but probably the main one was that I wanted to recollect the one that “got away,” well, the one that I let go. Errant short-sighted judgment, as is common in youthful people. So I built a replica M16A1, circa mid-60s, well, of course, with only two selector stops. At the heart of that rifle is an original-spec barrel, chrome-lined, NATO chamber.

5.56 stamp
This is a NATO chamber stamp. If it’s “.223 Rem.” that’s NOT the same!

That’s leading to this: I opened up a few boxes of “genuine” NATO 5.56 to check it out with, something I honestly haven’t fired for years and years. Dang. That stuff is potent. Over the past several years, the pressure level has increased. Current standard is a little over 62,000 PSI. (NATO is technically measured differently than commercial, but the figures I give here are accurate for comparison.) Compared to SAAMI specs for .223 Remington (commercial) that’s a solid 7,000 difference. (That SAAMI-spec figure has likewise increased over the years, judging from recent test figures I’ve seen respecting commercial .223 Rem.; most references heretofore were max at 52,000 PSI.)

The main impetus for this article, though, came from a recent experience at a local gun shop. I went in search of a sub-sonic .300 Blackout load, and they had one in .300 Whisper. The counter person told me that it was “exactly the same as .300 Blackout, just like .223 is the same as 5.56…” Whoa. Neither statement is true, although Whisper specs are plenty close enough to Blackout that no differences factor in safety or function. However! I didn’t take the time to lecture, but, dang, .223 Rem. and 5.56 NATO are not nearly the same.

First point: do not fire NATO-spec ammo in a rifle with a chamber marked “.223 Remington.” It will, not may, be over-pressure. Reasons have to do with chamber specifications for 5.56x45mm NATO and those for SAAMI-spec .223 Remington. There is a significant difference in the leade or “freebore” cut comparing SAAMI to NATO. That’s the space in a chamber ahead of the cartridge case neck area that leads into the rifling. NATO is radically more generous, meaning “bigger”: longer, more volume. (About 0.150 inches, based on my measurements of bullet seating depths that touch the lands.) There is relatively much more room for expanding gases to occupy in a NATO chamber. In a SAAMI chamber there’s much less room for expanding gases to occupy. The additional pressure is about the equivalent of another full grain (or more) of propellant in the case. Yikes.

high pressure nato
Here’s what happens putting a factory-fresh NATO round through a .223 Rem. chamber. This case is clearly beat. Sure, it might, should, hold up for that firing, but the case is done and the gun took a needless hammering.

nato beat case

There are other little nit differences to pick between the SAAMI and NATO cartridge, and, therefore, chambering specs, but they don’t really factor in a material sense. There’s bound also to be just as many small differences in cartridge dimensions from one maker to the next. I’ve measured enough to tell you that’s true.

Now. What this has to do with reloading (finally, I know) is based on a question I’ve gotten over the years, a concern to some, or at least, as said, a question. And the answer is that you’re better off going with .223 Remington loading data for any ammo intended for “general” range use. That means blasting away on an afternoon. Just because it’s a NATO chamber does in no way mean you’re supposed to run NATO-spec ammo through it! Back it off and enjoy it more.

If you’re relying on a factory-published data manual to give a place to start, or stop (something from Sierra, Hornady, Lyman, or so on) pay very close attention to the test barrel specifications. Clearly, barrel length has a big influence on attaining the published velocities, and some load combinations are going to be worked up using considerably longer barrels than what the most of us have on our AR15s. But the biggest factor is the chamber used in the test barrel. If it’s a SAAMI-spec (sometimes called a “SAAMI-minimum”) chamber then the data should be on the conservative side. Should be. Do not, however, bank on any idea that you should jump straight to the maximum load listed if you’re loading for use in a NATO. There are, always, too many factors that otherwise create more or less pressure (primers, cases, propellant lot, and more).

As time goes by it probably is less likely to encounter a semi-automatic “.223” that’s not a NATO, but it will be marked as such! Clearly, most ammo is used in the most popular guns. That’s not going to be a bolt-action anymore. Make no mistake, though, AR15s exist plentifully that have SAAMI chambers, and I see a lot of aftermarket barrels that are cut with that minimum-dimension reamer.

ANOTHER OPTION
So what’s a “Wylde” chamber? This is a chambering spec developed by Bill Wylde, one of the early and leading pioneers in the quest for improved AR15 accuracy. It is popular and available, especially in aftermarket barrels. What it is, is a chamber that’s in-between SAAMI-minimum and NATO, leaning closer to NATO. Rumors are true: it’s safe to fire NATO-spec factory loads through a Wylde. The Wylde was designed upon the introduction of the heavier competition bullets with the idea of providing more freebore to accommodate the necessarily longer cartridge overall lengths necessary with something like an 80gr. Sierra, but keep the amount of jump to a minimum with shorter bullets fed from the magazine.

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Why Not Flat-Base?

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A better question, given that the vast majority of popular rifle bullets are boat-tail, is why flat-base? KEEP READING

flat base bullet

Glen Zediker

Good question! I have something that at least has elements of an answer.

A boat-tail bullet is the standard for the majority of rifle bullets, and the domineering choice of long-range shooters. Competitive Benchrest shooters favor flat-base bullets. Flat-base is also popular with varmint-hunters: the stellar Hornady V-Max line for good instance.

Hmm.

We all want best accuracy, so why the difference? Consider the overriding characteristic of a flat-base bullet: it’s shorter. Now, since not all flat-base bullets are shorter overall than a same-weight boat-tail (they’re usually not), I seriously need to clarify that!

Clarification: a flat-base can be shorter, and lighter, than it would be if the same ogive or nosecone profile used then added a boat-tail. More: if they’re both the same weight and at least similar in profiles, a flat-base often has a longer bearing area than a boat-tail bullet, again because the boat-tail is sticking down there, or not. These are both a bonus to Benchrest or any other shorter-distance circumstance where utmost precision is the goal. (When I refer to capital-b “Benchrest,” I’m not talking about a shooting rest, but a competitive sport.) Shorter bullets allow slower barrel twists (bullet length, not weight, chiefly governs needed twist). Slower twists offer a miniscule improvement in damping a bullet’s orbital pattern in flight, and considering the likewise near-caliber-size 5-shot groups these folks are after, that matters. Bullets fly in a spiral, like a well-thrown football. Again comparing those with similar profiles, flat-base bullets stabilize faster and sooner than boat-tails, it’s a smaller spiral. Bullets with longer bearing areas tend to shoot better “easier,” less finicky. And, flat-base bullets can provide more cartridge case capacity.

vld and ld compare
Here’s unique. Jimmy Knox of the original JLK Bullets once made flat-base versions of his Davis-designed VLD (very low drag) boat-tails. So this is a .224-caliber flat-base 65gr LD (low drag), which is the same as his 80gr VLD shown with it, just no boat-tail. Why? It was more of a “Why not?” Idea was to provide better downrange performance for those with slower-twist-rate barrels, and to retain the flight pattern and in-barrel characteristics he liked about flat-base (and way on more speed). This idea was popular among some better High Power shooters about 15 years ago.

All those good points make it sound like flat-base provide superior accuracy. They might. By my experience, they do, but! Distance defines the limit of that truth.

The boat-tail provides an aerodynamic advantage, and the farther it flies, the greater this advantage. There are well-founded beliefs that boat-tails are less influenced by gas pressure thrusting against the bullet base. A good and most knowledgeable friend at Sierra told me that a boat-tail has an effectively more concentric radius at the base due to the junction point created by the angle on the tail and the bearing surface. Further, a flat-base, is, in effect, harder to make so that the base will have a radius that’s as concentric with the bullet bearing surface. Manufacture care and quality (related), of course, makes that more or less true or false. If the idea is that a good boat-tail is “easier” to make, that this shape makes the end product more forgiving of manufacturing errors, then I’ll accept that since it’s pretty hard to argue against, but, again, I really don’t think that boat-tail designs simply take up slack in quality tolerances. I’m sho no rocket-surgeon but I know that the tail slips the air better.

LD_ and Hornady 68
Same LD bullet compared to a Hornady 68gr HPBT. The 65 is a tic shorter overall but, because it’s a 15-caliber (!) ogive, way less bearing area (exception to the “rule” big-time) than the boat-tail next to it. The 65 had a higher BC but was über-tricky to get to shoot well. I could get these to just over 3000 fps in a 20-inch .223 Rem. Mostly because of the tiny bearing area.

This can get pounded completely into the ground because adding a boat-tail (and I’ll show a great example of just that) to a similar nosecone also adds weight to the bullet, and that increases BC. It’s not exactly a chicken-egg question, though, because the tail helps otherwise.

barts bullet
Here’s a 52gr boat-tail from Hornady (right) next to a 52gr custom Benchrest bullet. I said the overriding difference is that a flat-base bullet is shorter, but that’s not referring to overall length. A flat-base is shorter than it would be as a boat-tail, if the other dimensions were the same, and usually has a longer bearing area.

You might have also heard said that boat-tails shorten barrel life because the angled base directs burning propellant gases more strongly at the barrel surface. They do, and many steadfastly uphold that as a reason against them. More in a bit. However! Beyond 300 yards, at the nearest, there are no disadvantages in using boat-tail bullets that come close to surpassing their advantages.

There’s another debated advantage of a flat-base and that is they tend to shoot a little better in a barrel that’s about to go “out.” I’m talking about a good barrel that’s pushed the limit of its throat. That one is true too!

And speaking of barrel life, another is that flat-base bullets produce less flame-cutting effect than boat-tails. A barrel lasts longer if fed flat-base. True! Flat-base bullets “obturate” more quickly. Obturate means to “block,” but here it means to close a hole, which is a barrel bore, which means to seal it. The angled boat-tail creates a sort of “nozzle” effect. Can’t much be done about that, though, because when we need boat-tails we need them. That is, however, a big score of help for the varmint hunter.

There is a relatively obscure “combo” out there called a “rebated” boat-tail. This has a 90-degree step in from the bullet shank (body) to the tail. It steps in before the boat-tail taper is formed (they look like a flat-base with a boat-tail from a bullet a couple of calibers smaller stuck on there). It’s common for competitive .308 NRA High Power Rifle shooters, for instance, to switch from the popular Sierra 190gr MatchKing to a Lapua 185 rebated boat-tail when accuracy starts to fall off due to throat wear. Sure enough, the Lapua brings it back for a couple hundred more rounds.

rebated boat tail
Here’s a rebated boat-tail. 115 grain 6mm from David Tubb.

If anybody with heavy equipment making bullets for sale out there is listening: I’d like to see some more rebated boat-tail designs! It is, though, a challenge to make precisely.

So. What? So what? Well, if you are big into small groups, I very encourage some experimentation with flat-base bullets. Again, distance is the only limit to their potential goodness. 100 yards, yes. 200 yards, yes. 300 yards, no!

vld chamfer
One thing is for certain: Flat-base bullets are not nearly as easily seated! Some have an edge-radius, some don’t, but, they are very easy get started crooked, or difficult to get started straight, same effect. I strongly recommend taking steps to square case mouths and use a generous chamfer.

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: What I do…

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There are a lot of ideas and options when it comes to loading the “most important” ammo. Here’s the 5-step process I ended up with… READ MORE

dial indicator

Glen Zediker

I spend a lot of time telling everyone else what they should do, and probably more time telling them what not to do, or what they could do… I thought it might be best to tell you all exactly what it is that I do to prepare a batch of ammo for a tournament.

That’s a quick way to show you what, clearly and obviously, matters to me. I admit: I don’t always do all the things that I talk about. A big part of my role here is to pass along information, answer questions before they’re asked, in a way of looking at it. There’s information, and then there’s action, and that’s not a contradiction, to me. For instance, I can tell you all about case neck turning, and metplat uniforming, and many other preparation steps. I have done them all, sometimes do them, but dang sho not always.

Believe me: I have tried everything and much, much more than I’ve ever talked about in these paragraphs.

Following is what I have found works to my satisfaction. Since I’m dealing with a fair amount of cartridges at any one time, there is, no doubt, a time and effort element that’s important to me. In other words, what’s coming next are the things I really think I must do to give my score the best boost I can reasonably give it.

Step One: Get my cases together and size them. I load in 100-round batches, so I start with five boxes, or whatever corresponds to 100 rounds. Without so much as a second glance, I run them all through my full-length sizing die: lube each and cycle it through. If nothing else, most new cases are not nearly ready to load. The case necks are usually banged up, not round, so at the least I’d need to size the inside and outside of the case neck, and I’ve found that, while other appliances will suffice for that, it’s just easiest to use my sizing die.

Step Two: I trim them all. This isn’t done as any matter of safety, just consistency. I set my trimmer to at the least touch each case mouth. This is very important! The next prep steps rely on having cases that are all the same length.

case trimming

Step Three: After chamfering inside and outside (I use a 17-degree on the inside and a standard tool for the outside) I run a flash hole uniformer through each. This is why it’s important to have them all the same height. That way the uniforming tool cuts to a consistent depth.

inside uniformer
After full-length sizing all my new cases (to mostly get the necks shaped up), I trim all the cases to ensure length consistency to start, because the next procedure, inside flash hole deburring, demands it. Shown is from Hornady. CHECK IT OUT HERE

Step Four: Primer pocket uniforming. I run each through this process. Now, I have had some lots of brass that make this normally simple process a chore, and that’s because the reamer is too snug a fit to the pocket. We all know that primer pockets are at their smallest on new cases. That is, by the way, one reason I’ve mentioned that the primer pocket “feel” is a leading indicator after the first firing as to the pressure level of the load. In keeping, there are times when I wait until recycling the first-fired cases before running the uniformer. It depends on how readily the cases will accept the reamer.

primer pocket reamer
Primer pocket uniforming is an important step in my own process, but sometimes I wait until the first-firing. Depending on the tool used, and how much power can be applied to assist, this job can be a chore on a tight pocket. Shown is a Lyman tool. CHECK OUT TOOLS HERE

Note: I consider my “best” ammunition to be that which I load on my once-fired cases. At the same time, I won’t hesitate to use new cases for a tournament (but not for a Regional or bigger event). Over a whopping lot of time keeping notes, my “second-firing” rounds tend to shoot a tad better, but it’s a miniscule amount. That’s why I don’t really sweat over the primer pockets on the first go-around.

Step Five: Roll them all! I run all the cases through a concentricity fixture, aka: spinner, to check runout. I segregate on the following criteria: “flatliners” no visible runout, less than 0.001, 0.001, up to 0.0015, more than that… Five piles. One reason I do 100-round batches is because I need, technically, 88 rounds for a tournament. Since I am using “name-brand” brass, I easily find my 44 prone-event cases that are going to be no more than 0.001 out of round. The remainder are proportioned better to worse for the 200 yard events. It’s not that I don’t think each round matters, because it does, and, honestly, the 200-yard Standing event is what wins a tournament, but that’s way on more on me than the ammo. A case with 0.015 runout is not going to cause a “9.” That case will produce groups way inside the X-ring.

Co-Ax Case and Cartridge Inspector
I segregate using a runout indicator, a tool shown before in these pages. Some argue, logically, that the best way to find cases with the most consistent wall thicknesses is to measure wall thickness, but, my experience has shown that, ultimately, concentricity is the result of wall thickness consistency. Sho is faster. Shown is a Forster Co-Ax Case & Cartridge Inspector

Now. I fully realize that segregating by runout, concentricity (“centeredness”), is not the same as actually measuring case neck wall thicknesses. However! “Flat-liners” are what ultimately result from consistent case neck walls. Since I have also sized the inside of the case neck, not just the outside, the spinner does give an accurate indication of case neck wall consistency.

case segregation
After sorting by runout, here’s what I get, or what I got once… These were graded (left to right) 0.0000 (no perceptible runout), up to 0.0010, 0.0010, 0.0015, and more than that. So, here, there were 37 cases that were at or near the level of neck-turned cases, and another 37 showing only 0.001, but way on easier.

Since it’s often the night before that I’m doing this, spinning is way on faster than measuring…

Then I prime, fill, seat. Get some sleep.

This article is adapted from Glen’s books, Handloading For Competition and Top-Grade Ammo, available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com

RELOADERS CORNER: Pressure Signs

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We usually want the most velocity we can SAFELY get, and here’s all about how to stay safe. Keep reading!

Glen Zediker

I’ve been on the topic of load development — “working up” a load — for the past couple of editions, and, based on the excellent feedback from you all, here’s more. As always, there’s only so much I can write before I have to cut myself off.

I’ve said that velocity is the initial leading indicator of pressure. Velocity, in itself, however, is not a definitive indicator of pressure. I’d like to clarify… The first point is that I am a big believer in establishing a goal for load development, and, for me (and likely most others) that is a velocity. Accuracy is a given! I will never consider a combination that’s not shooting little knots downrange, but accuracy and velocity are not mutually exclusive. I also would never consider a combination that produced very small groups at an unacceptably low velocity, and that’s because I’m shooting (always) beyond 200 yards. The super-accurate low-velocity load gets its bullet shifted that much more in a variable wind, so it’s way on less likely to maintain those small groups.

I want to hit the velocity ballpark I have in mind and that’s why chronograph readings as I’m incrementally increasing the propellant charge are my leading indicator to how close I’m getting. I am also, always, looking for pressure signs on the spent cases — each and every one ejected.

So about those pressure signs…

Primer condition gets first attention.

primer pressure signs
Middle is what I want to see: pretty much a new primer with a nice round dimple in the center. Right, well. Massive pressure! But notice that the primer still shows a radius on the edges and is only a little rougher in appearance, well, aside from the crack…

A primer should have a smoothly dimpled firing pin indention, a shiny appearance, and a visible radius on its edge. If any of those are missing or compromised to varying degrees, there’s your sign… A dull and flattened primer has been abused, as well as one with a pitted or cratered appearance. Clearly, a crack or leak (indicated by black fouling) is way over the limit. After experience, backed up by gauged measurements, you’re liable to find that judging what’s “normal” and “safe” from one rifle can be different from another. I have had individual guns that flattened primers at any point near a safe-maximum charge. And, I’ve had them that just lied. Unfortunately, small-rifle primers don’t show always show pressure signs as reliably as large-rifle primers (structural differences). I’ve had experiences where the primers are all nice and shiny like and then blow out with the next increment. Shame on me for taking it there, and, speaking of: don’t get greedy! That’s one reason a velocity goal is important. Despite what your kindergarten teacher told you, you’re not that special… If you’re reading another 50+ feet per second more than what consensus says you should, better bet you’re over-pressure. “We” went through a lot of that when coated bullets got popular: those changed all the rules for “maximums.”

flattened primer
Here’s flat. My experience has been that large-rifle primers tend to display this indication more so than small. What’s happened is that the primer has flowed quite forcibly to fit the confines of its pocket and the bolt face. It’s also normal for some rifles, but that just means you have to know: pay attention and back off if you see a flattened primer.

The best pressure indicators show at the loading bench.

primer seating
My best “gage” for pressure is seating a primer in a fired and resized case. It’s a feel, gained through comparative experience, but too easy means there was too much pressure.

The reason I suggest (strongly) doing load work-up with new cases is because you then have a baseline. Measure the case head diameter (on the case, not the rim or groove) on the new case and compare it to the fired case. Up to 0.0005 (that’s ten-thousandths) is really high but some say acceptable (not me), and 0.0002-0.0003 is what I’d prefer. Plus, since a new case is at its smallest, meaning it will have a little less capacity than a fired case, you’re getting some assurance that the pressure will likely be a little lower from the same load in subsequent reuses of that case.

All dimensions are at their minimum in a new case. Primer pocket expansion is related to case head expansion. I get (what’s proven to be) a very accurate indication of pressure based on the resistance to seating a primer in that resized case. You have to use a priming tool that gives adequate feedback (meaning low leverage) but if the primer just slips right back in, that load was over-pressure. In a more extreme circumstance, the primer won’t stay seated. Yes. I have seen that. Shame on me, again.

Finally, a new case easily points out the difference between a “pressure ring” and a “sizing line” that can show just above the case head along the case body. A bright ring there indicates excessive stretching (a sizing line comes from the die reducing that area, and is perfectly normal). That “pressure ring” sign is also likely an “improper headspace” sign, but that’s another article.

pressure ring
Here’s a “pressure ring.” This poor old fellah used to be a brand-new Lake City Match case. I suspect there was some issue with this rifle’s headspace, but if you see this bright stretch mark, red flag it! It means the case is going to crack right there next use (called an “insipient head separation”).

Pierced Primers
This is a common malady on AR-platform guns, and especially on the big-chassis versions (SR-25, AR-10, and similar). Pressure both isn’t and is the culprit and the solution. Lemmeesplain: What causes the pierce is a firing pin hole that is too large. It is not the fit of the firing pin tip to the hole! An engineer can explain it, but it has to do with surface area covered by the firing pin hole, and then along with it the surface area of the primer. Simply: the firing pin hole turns into a cookie cutter. A primer pierce creates all manner of ills, including wrecked firing pins, gas flow through the charging handle area (where your face is), and abrasive debris scattered throughout the lower interior, including the trigger parts.

firing pin hole size
Blueprints call for a 0.058-inch diameter firing pin hole on an AR15 bolt. If the hole is too large then primer structural failures (pierces) will, not can, rear up. Too big is anything more than 0.062 inches, and I’ve seen plenty bigger than that. I use machinist’s drill bits to quick-check bolts: 1/16 (0.0625) and #53 (0.0595). If the first fits the hole, find another bolt. If the #53 won’t go, use that bolt with confidence.
pierced primer
Notice that this primer doesn’t really show excessive pressure signs. Just has a hole in it…

Excessive pressure gets blamed for a pierce but what’s really going on there is that it’s not certain that amount of pressure would be judged as “excessive.” It’s just gotten high enough to bring on this result. So, yes, lightening the load will stop the piercing, but, in my experience and that of many others, the pierces can start happening before reaching what most might agree on is a max load. I say that because “we” are all shooting about the same bullet/primer/case/propellant combinations in NRA High Power Rifle (with respect to Service Rifle division AR15s, for instance). Seeing pierced primers before hitting the proximity of competitive velocities points to “something else,” and that is the firing pin hole.

In a truly over-pressure load, the primer can crack or blow slap out, but it won’t pierce.

The information in this article is from Glen’s newest book, Top-Grade Ammo, available HERE at Midsouth. Also check HERE for more information about this and other publications from Zediker Publishing.

RELOADERS CORNER: Incremental Load Work-Up

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To get the most from your load testing, in the shortest time possible, learn the “Audette Method,” and put it work for you. Here’s how!

sight in target
Use a target that’s, one, easy to line up on, and, two, lets you make notes on the target itself. I usually circle and note the 3-shot increments, or you can add a number by each shot hole to indicate which try they belong to. Midsouth has some HERE

Glen Zediker

Last edition I suggested taking the step toward putting together a “portable” loading setup to allow for load development right at the range. This time I’ll talk about an idea on getting the most out of a test session in the quickest and surest way.

I have followed an “incremental” load work-up method for many years, and it’s served me well. Some call it the “Audette Method” named for the late and great Creighton Audette, long-time long-range and Benchrest experimenter.

Backing up a bit: Being able to employ this method efficiently requires having spent the preparation time, doing your homework, to know exactly how much “one click” is worth on your meter. Whether the meter clicks or not, it’s the value of one incremental mark on the metering arm. The value of that click or mark varies with the propellant, but by weighing several examples of each one-stop variation (done over at least a half-dozen stops) you’ll be able to accurately increase the charge for each test a known amount.

harrell's meter mounted
I count on a Harrell’s Precision meter. Its Culver mechanism allows for easy and accurate incremental adjustments in working up a load. The dryer sheet eliminates static electricity.

I usually test at 300 yards. That distance is adequate to give a good evaluation of accuracy and, for the purposes of this test, is also “far enough” that vertical spreads are more pronounced. Testing at 100 yards, sometimes they all look like good groups… So it’s at about 300 yards where we’ll start to see more difference in good and bad.

Get to the range and get set up, chronograph in place. Put up a target. Use whatever gives you a clear aiming point, but it’s helpful to have a light background not only to see the holes easier using a scope, but also to make notes on. More about that in a minute.

Use the same target for the entire session. (Put pasters over the previous holes if you want, but don’t change paper.) The reason for using the same target for the whole session is that helps determine vertical consistency as you work up through successively stouter propellant charges.

I fire 3 rounds per increment. As it gets closer to “done,” I increase it to 5 or 6. At that point I’ve hit a couple of speed points, two or three increments that represent a performance level I can live with (one is on the “iffy” end of the pressure, and I rarely choose that one) and am focusing more closely on group size. Final confirmation comes with one 20-round group. For what it’s worth, I usually pick the one in the middle.

A 3-round volley might seem inadequate, but it’s not if there’s confidence that the rounds are being well-directed and speed is being monitored. If I’m seeing more than 12-15 fps velocity spreads over 3 rounds, I’m not going to continue with that propellant. Same with group size: if it’s a big group over 3 rounds, it’s going to be a bigger group later on.

I’m sho no mathematician-statistician, but from experience I’ve found that, while certainly there’s some probability that the first 3 rounds fired might represent the extreme edges of the load’s group potential, and that all the others are going to land inside them, uhh, that’s not even a little bit likely. If it starts bad it finishes bad. On the contrary: no, just because the first 3 shots are close together and the velocity spread is low doesn’t mean it’s not going to get worse. Groups normally get bigger and velocities get wider, but, we have to start somewhere. It’s a matter of degrees. Also, the quality (accuracy) of the meter factors, and the better it is the better you can judge performance over fewer examples. And this is new brass, so that’s going to minimize inconsistencies further.

I can also tell you that it’s possible to wear out a barrel testing. No kidding.

Back to the “incremental” part of this test: As you increase the charges, bullets impact higher and higher on the target paper. You’re looking for a point where both group sizes and impact levels are very close together. If the groups are small, you won! That’s what Crieghton called a “sweet-spot” load, and that was one that didn’t show much on-target variance over a 2-3 increment charge difference (which is going to be about a half-grain of propellant). The value of such a load is immense, especially to a competitive shooter. It means that the daily variations, especially temperature, and even the small variances in propellant charges that might come with some propellants through meters, won’t affect your score. It’s also valuable to a hunter who’s planning to travel.

audette method loading
Audette Method: If it would only always work this way… This actually did work as shown so I captured and recreated it for posterity. The numbers on the left represent approximate propellant charge weights and the lines each indicate one click on my Harrell’s powder meter, a value about 0.15 grains of the propellant used in this test. Going up two clicks at a time for eight tries took me from 24.0 grains to about 26.0, which is a good range from a reasonable starting charge to pressure symptoms. I didn’t add in the velocities since that’s inconsequential to this illustration, but will say that “8” was too much and I settled on “6.” To make more sense out of this illustration, that ended up being 25.5 grains — step 6. I also went up using three rounds and skipping ahead by adding more clicks to the meter after viewing the (low) speeds on the first three groups (that’s why there’s no number 4 step; I went from step 3 to step 5). This has a lot to do with intuition sometimes. Point is, and should be, that here’s how the “Audette Method” is supposed to work: impact elevation on target goes up (these were fired at 300 yards) with charge increases, groups get smaller (hovering around two inches for this test) and stay small, and then elevation begins to stabilize. Choose a load that’s within this range. Then it’s a “sweet-spot” load. If this happens in your test, ask for no more!

That was the whole point to following this process. First, and foremost, it’s to find a good-performing load. It’s also how you find out if the propellant you chose is going to produce predictably. I can also tell you that I have chosen a propellant and a load using it that wasn’t always the highest speed or even the smallest single group. It was chosen because it will shoot predictably all year long. I base everything on the worst group, biggest velocity spread, not the smallest and lowest. If that doesn’t make sense it will after a summer on a tournament tour. If the worst group my combination will shoot is x-ring, and the worst spread is under 10 fps, it’s not the ammo that will lose the match…

As said to start this series, I started loading at the range because I got tired of bringing home partial batches of loser loads. And, you guessed it, the partial boxes usually contained recipes that were too hot. The only way to salvage those was to pull the bullets. Tedious. Or they were too low, of course, and fit only for busting up dirt clods. Plus, I’m able to test different charges in the same conditions. It’s a small investment that’s a huge time-saver.

If you do invest in a portable setup, exploit potentials. The possibilities for other tests are wide open, seating depth experiments, for instance.

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The information in this article is from Glen’s newest book, Top-Grade Ammo, available HERE at Midsouth. Also check HERE for more information about this and other publications from Zediker Publishing.