Tag Archives: Handloading for Competition

RELOADERS CORNER: Bullet Seating Depth

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A popular topic in these pages, and for good reason: it can make a big difference in rifle accuracy! Read more about it HERE

benchrest bullets
Pretty much all bullets respond to seating depth changes. Long or short, for maximum accuracy it’s worth the effort.

Glen Zediker

Every time I do an article here in Reloaders Corner on the topic of bullet seating, I always see at least a couple of comments from readers about their experience and preferences with bullet seating depth. Those usually involve or revolve around seating a bullet so it is touching, or is nearly touching, the lands or rifling when the round is chambered.

This is a long-standing “trick” well known in precision shooting circles, like those competing in NRA Long Range or Benchrest.

Seeing What You’ve Got
First step, absolutely, is determining what the bullet seating figure is for your particular bullet in your particular chamber. This length is most often referred to as “dead length.” That’s a pretty ominous-sounding term! It’s not really perilous, but there is a little danger involved, which, mostly, is one point to respect. That point is that when a bullet goes from just off to just on — actually touching the lands — pressure will (not may) increase. Reason is that the previous gap-valve effect closed so burning gases are effectively “plugged up” a fractional millisecond longer. My experience with the most common small- to medium-capacity cases we’re using (ranging from, say, .223 Rem. to .308 Win.) is that this is worth about a half-grain (0.50-gr.) of propellant.

Finding It
Those who have read much in these pages have seen the Hornady LNL OAL tool. This is a well-designed appliance that will show you, in your chamber with your bullet, how far forward the lands are, or, more precisely, the overall cartridge length that will touch the lands. This amount varies and is unique! Don’t transfer figures from one gun to the next. It also changes… As the chamber throat erodes it lengthens, and so too will the overall cartridge length that touches the lands. Let’s call overall cartridge overall length COAL for sake of space.

hornady lnl gage
Here’s the tool to find the seating depth that touches the lands. Hornady LNL Oal Gage.

There are other means but I’ve not found one more accurate. Some smoke over a bullet that’s been seated into a “loosened” case neck and gauge contact by the marks left. This, however, is likely to be “touching, plus” length.

Once you’ve got the round ready to measure, I strongly suggest doing so using a bullet length comparator along with your caliper. This is another tool that’s been gone over and gone on about here. It measures at a point along the bullet ogive rather than on the bullet tip. It’s more accurate. Now. A comparator inside diameter is usually close to actual land diameter, but, as with chambers, these are each and both unique so don’t assume anything.

Hornady comparator
More precise reads come from using a bullet length comparator to measure overall length. This is a Hornady LNL too.

Why It Works
Setting the bullet so it touches the lands does a few things, all good. One, and I think one of the most influential, is that the bullet starts off aligned with the rifle bore. As a matter of fact, it better centers the whole cartridge because there is, not may be, at least a little gap between chamber and case. If there wasn’t the round wouldn’t enter the chamber. The bullet is, effectively, supported by the lands and that has, also effectively, taken up the “slack” by locating the cartridge more concentric with the chamber and bore. It also then effectively makes up for the affronts to concentricity created by case neck wall inconsistencies and the resultant relocation of the case neck center.

Another is that that it eliminates jump (the usual distance or gap between the first point of land diameter on the bullet nosecone and the lands). Bullet wizard Bill Davis (designer of the original “VLD” projectiles, and others of much significance) once told me that his thoughts on why especially the high-caliber-ogive high-ballistic-coefficient bullet designs worked best with no jump were for all those reasons and improvements just mentioned. Plus another: gravity. A bullet floating in space, and also moving forward in this space, has that much more opportunity to engage the lands at a little angle, if only because of gravity. Always have thought about that one.

Soft-Seating
There are degrees. When we go from just on to “in” that’s another tactic some experiment with. And it has another level that’s commonly popular with Benchrest and other precision shooters. That’s called “soft seating.” What that is, is setting the case neck inside diameter to very nearly match the bullet diameter with the idea that the bullet starts out extra-long and then chambering the round finishes the bullet seating when the bullet contacts the lands. The reason for the more generous case neck inside diameter is to reduce resistance so the bullet can more easily set back and let the lands seat it.

I don’t use this tactic, but have. It’s another level of commitment and, as is often true with such other levels, demands more attention and also limits utility. One is that it clearly is only for bolt-action use. Another is that it’s for single-shot use only; such rounds should not be loaded into a magazine or fed from a magazine. For another, once loaded the round can’t usually come back out. The bullet will stay and you’ll get an action full of propellant.

Seating Depth Experiments
Now this is a process I have used throughout. Most times I find that best accuracy comes with a seating depth that has the bullet “just” on the lands. Contact is made but it’s the same pressure level as if the bullet were sitting on the benchtop. I also often have found best group sizes come at a little less than touching, and, a few times, at a little more than touching. I’m talking about 0.002-0.003 longer than dead-length. Let’s call it “firmly touching” but also a long ways away from “jammed.” These rounds often can’t be extracted.

There’s an easy way to run seating depth experiments. Here’s how I do it: I load however-many rounds at dead-length plus 0.003 COAL. I load them all that way. I then take a small press I can clamp on to a benchtop or tailgate at the range, and install a micrometer-top seating die. For max accuracy, I already seated all these test rounds using this exact setup. Take along a caliper and comparator and a fresh notebook page. I’ve adjusted the propellant charge as said earlier by dropping it a tad. Now. I also know that there’s going to be a little difference in perfected results because of this because lengths that aren’t touching the lands are running 35-40 feet per second slower, but it still shows me what’s going to work best. If it ends up being a COAL with a little gap, I’ll bump it back up.

Last
As said, the COAL that works best is going to change because the throat is going to change. Check using the OAL gage and adjust. That means the load is also changing, a little bit, each time the bullet moves forward (more case volume), and that can affect zero and velocity.

It’s a lot to keep up with.

Another note: If you’re feeding these rounds from a magazine, and running them through a semi-auto match-rifle, make sure there is adequate bullet retention (difference between bullet diameter and case neck inside diameter, go good 0.003 inches). Don’t want the bullets jumping forward (inertia-induced). If, for example, you’re giving 0.002 hold-off, that little bit can get taken up easily and then, if the bullet gets on the lands, there’s a pressure spike.

GAGES, on sale now at Midsouth!

The preceding is a specially-adapted excerpt from Glen’s book Handloading For Competition. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

 

RELOADERS CORNER: Understanding Ballistic Coefficient

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Math and myth both get involved in bullet Ballistic Coefficient discussions. Keep reading to separate the two and learn exactly what BC is, and what it isn’t. MORE

bc

Glen Zediker

Years ago I explained in great detail to a fellow here all about ballistic coefficient and how it was calculated and how it could be used and how it can change and so on, and he stopped me: “So you mean it’ll hit furtherer on up the hill…” That’s it.

A “ballistic coefficient,” or “BC,” is a number assigned to a bullet that suggests its aerodynamic performance.

That’s a key word, “suggests.” The main suggestion is how well this bullet will fly compared to that bullet, and the one with the higher BC ought to fly better. Fly better means less drop and drift, and those, factually, are a product of the higher-number BC. My best all-inclusive definition what a higher BC does for us: less speed lost over distance. Regardless of the muzzle velocity or the distance, one bullet with a higher BC will lose relatively less velocity over the same distance.

bullet blueprint
Here’s a blueprint. All the information needed to calculate a BC is contained here. It doesn’t have to be a real bullet because a BC model is not a real bullet either. Design factors that influence BC are virtually every design factor: length, ogive, boat-tail, meplat, weight. These factors, in this instance, calculate to a G1 BC of 0.560. By the way, there’s about a 5 point BC increase for each added 1 grain of bullet weight.

BC is calculated based on a standard bullet model. There are 7 of those. Two are normally used to determine BC for conventional rifle bullets, like what the most of us reading this use. Ballisticians and designers know which model to apply to different bullet types. The common model is a “G1” (another is G7, which is becoming the popular standard for boat-tail bullets; G1 is based on a flat-base). The flight of this G1 bullet has been calculated at varying velocities and distances. It’s “all math” because a G1 does not in fact exist. BCs are derived by comparison.

g1
The older standard for most rifle bullets was the G1. The newer, and better, standard is the G7. However! BC is never chiseled into stone regardless of the model. It’s a way to compare bullets, and a place to start figuring yours out.

g1 and g7

The standard bullet of any form-factor has a BC of 1.000. An actual bullet that’s compared to the model at points downrange will either be flying faster or slower than the model. If it’s moving faster, its BC will be greater than 1.000. If it’s going slower, it will be less than 1.000. It’s a percentage of the standard or model bullet’s performance.

Now. That is also all that it is!

BC is not an infallible factual statement about precisely what a bullet will be doing when it’s loaded and fired at that target than moment with that rifle. Not nearly, not hardly.

To me, BC gives us a place to start estimating drop (elevation) and also clues to how much it will get moved by a wind. It’s a way to compare bullets.

BC changes! Day to day, place to place, hour to hour.

Some bullet makers publish a BC for a bullet based on actual testing (chronographs) but now it’s pretty much “just math.” That’s fine. Which — math or measure — provides the best information? Some believe that a measured, tested BC is more realistic and, therefore, more valuable. But, if the point is to compare bullets, calculated BCs is more reliably accurate.

We (NRA High Power Rifle shooters) have gone to difficult and frustrating lengths to collect data to calculate “real” BCs (chronographing at 500+ yards hain’t always easy). Measured BCs are quite often lower, and they are quite often higher. Reasons follow.

The accuracy of drift and drop tables clearly revolves around what the actual, at that moment, BC performance is from the bullet you’re shooting (compared to what it’s “supposed” to be).

Anything that can influence bullet flight influences the actual, demonstrated BC performance.

BC uniformity is important. Bullets that show uniform BC performance produce less elevation dispersion. A source for variation is the meplat (bullet tip). Hollowpoint match bullets are notorious for inconsistency in this area. There’s a tool, a “meplat uniformer,” that fixes it. That’s pretty much the point to the plastic points on bullets like Hornady’s A-Max line.

Atmospherics, which add up as a list of factors, have a huge influence on BC performance. Air density is probably the most powerful influence. Any conditions that allow for easier passage of a bullet through the air don’t detract as much from its stated BC as do any conditions that serve to disrupt its headway. BCs are based on sea-level so can easily show as a higher number at a higher elevation. I can tell you that bullets fired at The Whittington Center in New Mexico have a noticeably better BC than those shot at Port Clinton, Ohio.

Range reality is that the demonstrated BC changes from morning to afternoon and day to day and place to place. The calculated BC is not changing, of course, but the mistake is assuming that a BC is a finite measure of bullet performance.

Bullet stability is even a factor. For a stated BC to be shown on a shot, the bullet has to be “asleep.” If it’s not stable, it’s encountering disruptions that will slow it down. The rotational speed of a bullet in a test can influence BC. We’ve seen differences comparing different twist-rate barrels, and the faster twists often show a little lower tested BC.

Factors that don’t matter in BC? Caliber. I’ve been argued at often over this next, but it is perfectly and absolutely true: BCs work the same regardless of caliber or bullet weight. Two bullets that each have a 0.550 BC, for instance, behave the same. That’s helpful, and at one time was more helpful than it is now. When we had to use paper tables to get drift and drop data and there was a new bullet that didn’t yet have those tables done, all you had to do was find data for another bullet with the same BC, go to the same muzzle velocity, and that data was 100-percent accurate. A .308 and .224 that both have the same BC share the same table. Remember, it’s not “real,” it’s a mathematical model.

So if you take a load to the target one day and you’re putting on more elevation than the BC-based calculation says you should, the BC isn’t wrong. The day is just different.

Finally, does it matter (really) if a bullet BC is based on a G1 or G7 model? Debates continue. But, not really, and I say that because BC is still only a suggestion. G7 is a more closely matched model to what we’re usually shooting when we think of a “high-BC” bullet, but all the same factors day to day also influence its accuracy. Given access to the data, I definitely, though, go with G7 calculations to have a place to start from. My experience has been that there is less difference in varying conditions, but, again, it’s still (plenty) enough change that you cannot dial it in and win anything…

The preceding is a specially-adapted excerpt from Glen’s book Handloading For Competition. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Case Trimmers

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An ideal case trimmer provides precision, speed, and affordability. Here are some ideas on avoiding compromise. READ MORE

Hornady Cam-Lok
Hornady Cam-Lock. Good trimmer at a fair price. See it HERE

Glen Zediker

At some point, or points, cases need to be trimmed to a shorter length. Brass flows. Therefore, a case trimmer is pretty much a given in the tool assortment for any handloader.

There are needs and wants, realities and ideals. That’s true with many things, and applies often to reloading equipment. Ideally, a case trimmer will go beyond just trimming the case to a shorter length. They all do that well enough. I think it’s important that a case has a square mouth — dead flat across the top. This is an asset to getting a bullet started well into the case neck during the seating operation.

A Good Trimmer
There are a variety of trimmers available from most of the popular industry tooling suppliers. And most follow a pretty similar form and formula: a little hand-cranked lathe. In these, the back end of the case is chucked into a collet-type fitting. A caliber-size pilot that’s centered in and surrounded by a cutting head goes into the case neck and supports the front of the case.

Not nearly perfect! There are a few reasons and sources for reduced precision. The tool alignment may be true at each “end” of the trimmer, but the case we’re working with probably isn’t true. Mostly, since there has to be a gap for the pilot to freely rotate, and since case neck walls aren’t all consistent in thickness, the fit isn’t close enough to prevent out-of-round rotation. Along with the inevitable case body warp there’s bound to be a tad amount of wiggle. Since the case is supported only at its head area, not by its body, there’s flex afoot.

None of that means the case neck won’t get trimmed to a shorter length, which is the general idea. It does, however, mean that it’s not liable to be perfectly squared up.

LE Wilson
LE Wilson. See it HERE at Midsouth.

A Better Trimmer
I rarely just overtly recommend one tool over all the others, but after a good many years working with case trimmers, I can and will tell you that the LE Wilson design is the best I’ve yet tried. I guess, yes, that is just opinion, but it’s really not.

The difference in this trimmer design is that the case is supported within a sleeve by its body. There’s no polarized suspension front and back. Mostly, there’s no pilot. The cutter on an LE Wilson faces off the front of the case squarely. The sleeve holding the case sit atop a pair of rails and the whole arrangement excludes case condition from the process.

le wilson sleeve
Tap it in… Then tap it out…

le wilson sleeve

So why doesn’t everyone use one? Honestly, I’m not entirely sure. It is a different arrangement, and it’s not cheap, especially not if you accessorize the fool out of it with a stand, a clamping device, and a micrometer. It’s not more than the other higher-end manual trimmers though.

It’s also fast! There’s no clamp-twisting to get the next case in place, and back out again. The sleeves are slightly tapered inside so the case is tapped in and then tapped out. With a little experience it’s amazingly quick to get through your block full of brass.

Flexibility
Virtually all case trimmers can provide additional utility, do different jobs. The cutter can be replaced with a reamer, and some can get reworked into outside case neck turners.

My choice is usually a stand-alone station, and that’s mostly because it’s pretty tedious refitting the appliances. I am, or at least have become, lazy.

forster case trimmer
Forster. This is a good choice especially for those who want to make a multi-purpose tool out of their base unit. There’s a big collection of add-ons that let work over primer pockets, turn case necks, ream case necks, and even hollow-point bullets. Its precision is better than most.
forster accessories
A a few of the things that can go on a Forster. Very versatile tool!

As with all said about alignment for case length trimming, that is also all the same for using a trimmer for other chores. And, yes, I still think the LE Wilson works best as a reamer, for instance, and that is because all the alignment precision is built into the tool itself; the case doesn’t play a role.

About options, by all means fit up a “combo-head” if it’s available that will finish the trim with a nice inside/outside chamfer/deburr. Big time saver. These can be a trick to get set just right, but it sure saves time.

Power
It sure is nice to get a break from the crank! There are, though, as I see it, two kinds of power case trimmers. Those that replace the hand crank with an electric motor and those that are designed from the start to be powered.

Some trimmers offer a means to add your own power source, like an electric screwdriver or drill.

Gracey Match Prep
Gracey Match Prep. Pretty much a big motor! It’s intimidating on first use, but just push the case in and it gets trimmed (and chamfered). It’s way quick in use and produces precise results.

My favorite proprietary power trimmer is a Gracey “Match Prep.” Designed by the late Doyle Gracey as a fast and easy way to trim huge quantities of Lake City brass for NRA High Power Rilfe shooters, it’s a serious machine. It works like a gigantic electric pencil sharpener, at least in spirit. Pick up a case and push it forward into a collar and it’s trimmed and squarely faced. No clamps or sleeves. The case shoulder stops against the inside of the collar, so it’s imperative that all cases are resized prior to use. As said last time, though, that’s really the only time you’ll get consistent results with any trimmer.

gracey holder
A key to a Gracey’s speed is that the cases stop on the case shoulder: just push it it!

I don’t know how many cases I can trim in an hour because I’ve never spent an hour using a Gracey. I can easily do 100 in under 5 minutes.

Another very good power trimmer is the Giraud. Its essential means for and in operation are about the same as Gracey but it is a nicer package with more features. Gracey is pretty daggone simple. That’s not all bad. I’d say Giraud is the best, and its price does reflect that.

One Last
Again, it’s important to evaluate the overall condition of a batch of cases, related to how many uses they’ve had. Having grown a little longer isn’t likely to be the only thing that’s changed in a case that exceeds whatever limit you set for it.

And, speaking of, the “trim-to” length is usually 0.010 inches shorter than the maximum SAAMI-stated overall case dimension.

Next time we’ll look at tools used to treat the trimmed case necks and finish this task in fine style.

Check out some more options at Midsouth HERE

Gracey
Giraud

The preceding is a specially-adapted excerpt from Glen’s book Top-Grade Ammo. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Case Trimming

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We all have to trim bottleneck cases sometime. Question is when and how much, and then “how,” and here’s a place to start. KEEP READING

case trimmer

Glen Zediker

After going through that last series on keeping up with changes in cases resulting from their use and reuse, “flow” was a culprit behind the majority of detrimental changes. That is: Brass flows during firing. It moves from where it was to somewhere else. Since there’s a finite amount of material in a case, one place is getting thinner and another is getting thicker. The sources of the material, where the flow starts and where it stops, are primarily case necks and case heads.

To completely finish up on all this, the most obvious indication that there’s flow is measuring case lengths from base to mouth.

case trimming
The primary reason to trim is to keep overly-long cases from overrunning their space in the chamber. If the case mouth encounters the end of its allotted space, it can pinch in on the bullet, elevating pressure. Now, there’s usually a good deal of leeway before safety can be a question, but don’t push it…
measure case length
A caliper is the only tool needed to measure case length. It’s not really necessary to measure each and every case each and every time. It’s a whopping lot faster to set the trimmer so it just touches the shortest case you have (revealed through the process itself in setting up the trimmer) and trim all the cases using that setting locked in place.

First, and very (very) important: The ONLY time to check case length, or to trim cases, is after they have been sized! A fired, unsized case will be shorter than it was going in. The reason is because of the expansion in the case that resulted from firing. When the expanded areas are squeezed back to spec by a sizing die the case gets longer as it gets smaller in diameter, same as rolling a ball of modeling clay out on a table. After sizing is also the only time we can we know that the case shoulder area is consistent in dimension.

You’ll see two length figures published for your cartridge of choice: maximum length and trim-to length. Published trim-to length is usually 0.010-inches under what’s listed as maximum.

I got a gage umpteen years ago that could indicate the maximum case length a chamber could accommodate — technically, a “chamber length gage.” Man. I checked the chambers in my main rifles and found that they were all well more generous than the SAAMI-maximum. That didn’t really mean a lot, in fact, to how I proceeded. And it also didn’t mean I can advise ignoring the potential for danger in exceeding SAAMI-maximum. It just pointed out that there are differences in chambers, gun to gun, and at least showed me that not exceeding max stated length should easily keep you safe.

chamber length gage

If a case got too long, exceeded the amount of room given to it in the chamber, that would be a safety problem! The bolt may not close fully. And, if it did, the extra length would create a pinching-in constriction, and that would spike pressure.

We can easily imagine that there’s an influence from relatively longer or shorter case necks in their influence in consistently encasing the bullet. And I’m sure we’d be right. Trimming cases all the same should mean that all the case neck cylinders are the same height. Someone looking to maximize accuracy is liable to get worked up about that enough to trim each firing. I trimmed my tournament cases each use. And, no, none were remotely approaching maximum length. It’s reasonable to further suppose that more or less retention will influence velocity consistency.

Another performance asset may or may not happen, depending on the trimming tool chosen. But. A good trimmer will square the case mouth. I’ve seen a many new cases with a “half-moon” cut after trimming. A square case mouth helps a bullet start and finish straight when it’s seated.

case trimmer
Not all case trimmers are equal. We’ll talk more about some I like next time, and I’ll tell you why.

My routine for this sort of “accuracy-oriented” case trimming is simple — tedious, but simple. I don’t measure each case. I just run them all through a trimmer set to “some” length. Some are trimmed more or less, some just show a bright scuff on one little bit of the case mouth, but they are then all the same length. If I can’t prove it in group sizes, it sho does set my mind at ease that all the cases are holding all the bullets more nearly the same.

For those rifles that aren’t tournament guns, the only concern is that none, indeed, become too long. Those I will check at that “4-firings-in” point. Some may have reached SAAMI-maximum, most won’t have, but all will be longer than when started. I start them at a figure close to suggested “trim-to.” Stop and think about it, and if there’s been overall a 0.010-inch length increase, that’s significant.

As with all things associated with use and reuse in semi-autos compared to bolt-actions, cases are going to grow more and faster in a gas-gun.

Another instance where it’s important to keep up with case lengths, and that, again, really has to do with making them all the same, is for those who crimp (with a conventional cannelure method).

Now, there’s zero harm in using a longer “trim-to” length, and that may be more popular than my method. These lengths are stated in reloading manuals. Keeping up with it over years, I’ve seen no difference in the rate of lengthening trimming longer or shorter; I trim “shorter” solely as a matter of consistency over the (short) life of my semi-auto cases.

Next time more about the tools.

Get started shopping HERE

The preceding is a specially-adapted excerpt from Glen Zediker’s book Top-Grade Ammo.

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

Glen’s newest book, America’s Gun: The Practical AR15. Check it out HERE

par15

RELOADERS CORNER: Cartridge Evolution

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Here’s a short retrospect on what’s set the standards for most new cartridge designs, and why… KEEP READING

Glen Zediker

ppc

I’m not an engineer, but, like all of us, we rely on those folks to develop just about all the things we have and use. When we look at a new development, one that’s proven to work better than the “old” way, sometimes it’s easy enough to understand why. Cartridge development over the years is a good example.

What makes a good cartridge? Answers, of course, vary with the intended use, the performance needs. For the most part, power (which mostly is velocity), and “efficiency” (which is essentially getting the most from the least amount of propellant, likewise increasing barrel life), and accuracy (always) top the list. And, to me, “accuracy” is a combination of small group sizes and, even more, small group sizes all the time! Consistency.

Case capacity has the most to do with the first: more room for gunpowder means more power. Also, it’s pretty clear that pressures have been going up! There’s a big (big) difference in the pressure levels of some of the “new” cartridges compared to the older, longer-lived rounds. Sometimes it’s not because the older round can’t “take” the additional pressure, it’s because the guns might not. A round developed turn-of-the-century fits a rifle from the same era. Well, steel has improved, manufacturing has improved, and, some no doubt, is that the trend toward “shorter, fatter” cartridge cases also contributes.

So. About that…

In my mind, and certainly in my “world,” which is competitive shooting, one of the most influential cartridges has been, and still is, the PPC. That was developed in 1975 by Ferris Pendell and Dr. Lou Palmisano (hence “Pendell, Palmisano Cartridge”), and the idea was to design the “world’s most accurate cartridge.” They did. It has the record to prove it. However, that’s in Benchrest (capital “B” meaning formal competition). Bechrest is nearly always a 100-yard event. The idea behind the PPC wasn’t to set the range on fire with excessive velocity, although it’s well more rapid than others then popular in that game. The idea was to improve cartridge structure to improve shot-to-shot consistency, and another part of that plan was to extend the duration of load-to-load consistency by slowing down firing-induced changes to the case. It’s native caliber is 6mm (.243).

(By the way, the PPC is based on .220 Russian, which is still how many get their brass: fire form it from that. That round is associated with 7.62X39mm, which came earlier and was based on the WWII German 7.92x33mm Kurz, the Mittelpatrone.)

PPC and .223
PPC isn’t for everyone. It’s expensive and not nearly the fastest available today. However, it sho has had its influence on modern rounds. It’s expensive, by the way, because of the available brass: it’s from Lapua or Norma and has machined primer pockets, and other such points of perfection. Compared to .223 Rem. (right) which, in configuration, follows pretty well accepted architecture, similar to .30-06 and other originally-mil-based rounds, the PPC is shorter, larger-diameter, and longer-necked.

A few reasons, offered by its creators, why PPC shoots so well: One, it’s a short case, a scant 1.515 inches overall. That makes it more rigid and less susceptible to warp. It also means it fits into a short action, also more rigid (and with shorter bolt travel). The case neck is relatively long, which means the entire shank of the bullet is within the neck, never below it. That means no influence from varying cartridge wall thicknesses (the case neck walls can be made near-perfectly consistent), avoiding the case neck “donut” at the neck, shoulder juncture. Its body area diameter is 0.440-vicinity, which is (was) a good deal larger than the more common 0.378 commonly used in Benchrest. Case shoulder is 30-degrees.

About that: Well before the PPC there was P.O. Ackley. Well-known for his “Ackley Improved” rounds, which, pretty much, were standard rounds with a sharper shoulder angle. In sharpening (flattening) the shoulder angle (usually from 23-degrees to 30 or even 40), that also elevated the shoulder, and that increased case volume. More speed! Another benefit of the sharper shoulder was a notable reduction in the “flow” of the brass. That meant less change firing to firing. The sharper angle on the shoulder essentially “caps” the flow in that area.

ackley improved
Dang. These always look so radical, but it’s a proven formula: the Ackley Improved. My Dad used one of these in .270 decades ago (P.O hisseff built his rifle) for elk hunting. Shown is an AI 280 Rem. which nearly equals the power of 7mm Magnum.

Other attributes engineered into the PPC have and haven’t been incorporated into subsequent new cartridges. Notable is the smaller-than-standard flash hole. This requires a likewise smaller sizing die decapping pin. Also, PPC uses a small rifle primer, which is fitting based on its overall round size. Over years, there have been retro-engineered common rounds with small primer pockets and those have worked well. For a spell, over the time it was available, small-primer .308 Win. brass found great favor among competitive shooters. Remington made it. Interestingly (again from a perspective of one who isn’t an engineer) pressures were higher compared to standard loads based on routine large-primer brass. Velocities tended to be more consistent.

Another reason for PPC perfomance is one I don’t pretend to understand, and that is its “efficiency.” That’s all in the science of internal ballistics and I only can attest to its influence. I have been a PPC user (the 22 variant) for a good while. It’s what my main NRA High Power Match Rifle is chambered in (AR15 platform). From virtually the same amount of the same propellant, there’s a solid +100 fps gain over the .223 Rem. The structure of the PPC indeed “works.” From that, and from “those” (High Power shooters), rapidly evolved experimental takes on the essential PPC.

Moving on, rounds like 6BR and 6.5 Grendel are outgrowths of the PPC format (“upgrowths” actually: they’re bigger capacity). We’ve also seen the essential influence in the popular 6.5 Creedmoor and the 6XC, which currently dominate competitive across-the-course and long-range shooting (“standard” long range, not the 2-mile stuff, that would be .375 Cheytak…).

6.5 grendel
Cuzzin to PPC is 6.5 Grendel (left), which grew from earlier experiments by NRA High Power Rifle shooters in creating PPC “tall-boys.”

Looking at semi-auto developments, many of which have been coming at us fast and furious, it’s clear cartridge developers are exploiting these same ideas. There is a (short) limit on what will fit into an AR15 upper receiver, for instance, because, one, it’s a finite amount of space, of course, and, two, there’s a magazine box, and these are related. More power in this platform means a fat case.

Now. I am in no way suggesting anyone run out and tool up for PPC in the next rifle! It can be soundly beaten in the “real world” of our needs from a cartridge. There are similar rounds with more velocity, easier availability, lower cost, and on down the list of desirables. In the next couple of issues, I plan to talk more about some of the newest rounds, but wanted to offer just a little retrospect on where it all came from before getting into where it’s gone!

This article was adapted from content in Glen’s newest book: America’s Gun: The Practical AR15. Go check it out HERE

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

Check out AckleyImproved.com

RELOADERS CORNER: Improving Die Performance: 4 Simple Modifications

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Here are 4 low-to-no-cost setup tricks that will improve the concentricity of your loaded ammo. READ MORE

Glen Zediker

Cartridge cases and reloading dies all have centers. Trick is getting the centers to agree. When they do then that’s an asset to “concentricity,” and that’s attaining a major goal in the process of making better ammunition. A part that’s under pressure and moveable, such as a cartridge case being sized or a bullet being seated, moves toward a path of least resistance. If all associated tooling is “straight,” and the case itself is uniform, then the result is “straight.”

Accepting existence of tolerances and misalignments, taking steps to help two conflicting centers come close together comes from providing some free-play in the apparatus. I call it “floating,” and it serves to help, and here are a few ways.

To be clear: free-floating can help in two ways. One is to build-in float within the tool, and another is to create float and then use that to better center a tool. I’ll explain…

shellholder trick

1. Shellholder
Reloading presses with conventional shellholder arrangements use a spring clip to retain the shellholder in its slot. Remove it! It sits the shellholder off on an angle.

Get to a (real) hardware store and get an o-ring to secure the clip. The o-ring goes around the slot previously occupied by the clip. To install the shellholder just roll the ring down, slide in the holder, and the o-ring will pop back up to block  shellholder exit. Normally, the size needed is 7/8-inch outside diameter, 11/16 inside diameter, 3/32 thickness.

With the clip gone, the shellholder sits flat, as it should, and since the shellholder is free to move also allows some “wiggle room” so the cartridge case can center itself as it enters the die. This honestly makes a positive difference, especially in bullet seating, it seems.

NOTE: for these next “tricks,” choose a case that represents your “best,” one that’s got the most consistent neck wall thickness.

indexing dies on reloading press
Always put an index mark from die lock ring to die body to press top. That’s a simple way to verify return to “zero” when a die is installed back into your press. And ALWAYS install and remove the die holding ONLY the locking ring! Never the die body. Any bit of body rotation within the locking ring requires repeating the process of die adjustment.

2. Sizing die lock ring
Speaking of “wiggle room,” there’s just a little too much of that in a 7/8-14 thread. It’s pretty coarse. Taking up the play created by thread-to-thread gaps results in “straighter” die installation.

Always (always) secure a die body locking ring when there is a case inside the die, and with the ram in its fully upward position (press handle all the way down). This bit of pressure helps bring the die into better alignment. It also makes the die difficult to remove after snugging down the lock ring. Just get stout on it, and, after initial removal, subsequent re-fittings are easy. I use a “strap wrench” (plumbing supply and auto parts stores will have one). “Channel-Lock” pliers also work, but result in cosmetic, but not real, damage. Lock rings with wrench-flats are the bomb.

Before initial removal of the die after the snug-up step, draw an indexing mark from the die body to the die lock ring to the press top. That’s a simple way to return to “zero,” and also to know if anything got out of kilter. Use a paint marker.

3. Sizing button (expander) / decapping assembly
To get the sizing button in a sizing die holding on center, loosen the decapping stem lock nut and run a case fully up. Then slowly retract it until you feel the button enter and lodge into the case neck. Now. Put just a little pressure back in the “up” direction (down on the press handle) and then tighten the decapping stem lock ring.

This really makes a difference, by my notes.

adjust sizing die expander
When it’s possible, and it almost always is, secure the pieces-parts when they’re doing their jobs. For instance, tightening the locking rings on a decapping stem when the expander is holding inside the case neck helps bring the stem into straight alignment, and the expander along with it.

4. Bullet seater
Follow the same die-body-lock trick, after a bullet has been seated, and also just in the same as described for centering the sizing button (just keep the pressure “up” rather than retracting the handle) while you lock the seating stem. Flushing the die body makes a difference. Centering the seating stem may or may not, depending on the style of seating die you have. The “sleeve”-type seaters (like the Redding Competition) are already in alignment so the seating stem itself can’t be influenced. As said, the body can get a help.

index sizing die
O-ring trick: the flexible ring allows for some “wiggle room” to help case and die centers match. Trick is reinstalling the die to hold the desired setting, and the index mark really helps.

One more: Lock-ring o-rings
Here’s another trick I can suggest, but don’t really use… That’s because it, indeed “works,” but I prefer these other means. The trick: install an o-ring under the die body locking ring (for sizers and seaters). This allows some movement, positioning flexibility, in helping a case center as it’s entering the die.

If you do this one, most definitely index-mark the die ring to the die body and then the ring to the press top, as suggested. Never touch the die body itself to thread in or out the die. Hold only the lock ring! (And that’s true regardless.) O-ring size is 7/8-inch inside diameter and a thickness of 1/8-inch.

NOTE: My topics over the past few editions have tended be a tad amount “nostalgic,” and there’s some reason. I just finished a new book, and this one took me way on back to the start of when I discovered reloading, which coincided with discovering my first AR15. It’s called “America’s Gun: The Practical AR15.” It will be available here soon, but not just yet. But go take a look! Information is on my web site HERE. I’m really proud of it. 

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 Happened To Moly-Coated Bullets?

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All the rage in 1998 and all but dead 2018: here’s a look at some reasons why. KEEP READING

moly coated bullets

Glen Zediker

In a way, I guess nothing really happened to molybdenum-disulfide-coated bullets (“moly-coated”). They’re still for sale, as are means to make up your own. What I mean is why didn’t they attain the sustained popularity they started with about 20 years ago, back when many forecasted they would virtually replace bare bullets? Here’s my take, from my experience, on “what happened.”

I don’t know any shooter who tried them and wasn’t excited about results. I sho was!

Performance-wise, moly has a lot of benefits. A lot. The first and most: take two bullets, one coated and one bare, put the same load behind them, then shoot and chronograph. The coated bullet goes slower. How is that a help? The reason it goes slower is because moly drops chamber pressure (into and through the bore easier). And! That velocity loss (at least 50 fps, usually more) is not, proportionately, nearly as much as the accompanying drop in pressure (usually ballpark 4000+ psi). (These figures vary with the cartridge, but all show similar universal influence.) So. The moly-load can be increased beyond previous “maximum” velocity: the idea is to take the coated load up to normal chamber pressure. It works! It’s common to need at the least 1+ grain more propellant to level the coated load with the original bare-bullet load.

Other advantages: Most see improved velocity consistency, evidently resulting from the coating alone. The coated bullets seem to have no limit to the number of rounds that can be fired with no change in accuracy or impact location. Of course there is a limit, but I knew many going beyond 500 rounds between cleanings. And when I say “many,” I’m talking about serious competitive shooters. Another benefit is increased barrel life (less rapid throat erosion), and this is, I think, due to a faster-accelerating bullet getting into and through the throat more quickly (less intense flame). Moly bullets also release sooner from the case neck (additional “tension” is recommended).

I “switched.” (The motivation to write this came from a weekend shop-cleaning where I restacked a huge many boxes of coated bullets, and wondered if I’d ever shoot them…)

I got more bullet speed and zero loss of zero: big benefits to an NRA High Power Service Rifle shooter. 88 rounds per day, and 80gr bullets through a 20-inch barrel trying their best to get to 600 yards in close proximity of one another.

moly barrel cleaning
Here was my solution to cleaning up after moly: Kroil penetrating oil and abrasive-type bore paste. This combination got it gone, and zero didn’t leave in the process.

What is bad, then, about moly-coated bullets? Moly itself! It coats the bore with a layer of residue. This layer traps moisture and will, not can, corrode the steel underneath it.  More: molybdenum disulfide outgases (outgas is the release of an occluded gas vapor that was part of the compound; a state change, pretty much) at lower than firing temperatures. That creates a chemical that, when mixed with water (including post-firing condensation), becomes, pretty much, sulfuric acid. That meant that the whole “zillion rounds between cleanings” didn’t really work. I know many who “lost” barrels, expensive barrels.

If the barrel is cleaned (correctly) after each use, no problems. But then another advantage is lost because starting with a clean barrel it takes quite a few rounds to return to zero. The layer has to be recreated.

The residue is x-difficult to remove. It doesn’t respond to routine means for bore maintenance, mostly meaning brush-and-solvent. The only way I found to get it gone was using micro-penetrating oil in conjunction with an abrasive paste-type cleaner, such as USP Bore Paste or JB Bore Compound.

bn coated bullets
Boron Nitride (BN) is an alternative that functions, in my experience, the same but with fewer drawbacks. One is that it’s “clear,” not as messy. Bullet on the left is coated. Still, though, I think that shooting coated bullets is an “all or nothing” proposition. Good groups are not likely to come “mixing” bare and coated bullets through the same barrel.

I no longer use coated bullets. There are other coatings that have fewer disadvantages, like boron-nitride (doesn’t outgas), and some of the proprietary baked-on coatings a few major makers (like Barnes and Winchester) use don’t exhibit the post-firing issues “conventional” moly-coating creates (which usually was moly powder, followed by wax, which added to the tenacity of the residue).

However, another issue is that accuracy tends to suffer running bare bullets though a residue-coated bore (which results after only a few coated rounds, that are coated with anything). All that means, in short, is that running coated bullets is something that really has to be bought into. It’s a commitment, as I see it, and, as with many such things, pushing the limits on performance requires more attention to detail, more effort. It’s a matter of value.

lyman moly kit
Here’s an easy way to get bullets coated: Lyman’s Super Moly Kit. Just add a tumbler. The two bowls contain the media, moly, and bullets and then go into a vibratory-type tumbler. The 6 ounces worth of moly powder will coat thousands of bullets. It works well.

Weigh the pros and cons. I honestly cannot, and will not, tell anyone not to use them. Coating can provide a serious performance increase. I don’t use moly-coat anymore, but that’s because my shooting needs are not so “serious” as they once were. I, yes, have gotten a tad amount lazy. I want to go to the range and enjoy my rifles and not lose sleep over the possibility of creeping corrosion if I didn’t clean up. I also want to be able to shoot different loads, including factory ammo, and maintain accuracy.

Last words: IF you choose moly, take steps to protect the barrel bore against the potential for damage. At the least, run some petroleum-based oil through the bore after shooting if you can’t clean it soon.

Tell about your experiences with moly.

See what Midsouth offers 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: Cartridge Cases, the Outside, Part 2: Case Cleaning

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Clean means “not dirty.” More details coming next. READ IT ALL

clean cases

Glen Zediker

Clean brass loads easier, keeps dies cleaner (and may help them last longer), and might even help your barrel last longer. Brass collected up off the ground almost always has some manner of grit clinging to it and, depending on range locale, that will cause more or less concern. If it’s sand, for instance, this debris can do serious damage to a die (and barrel). Plus, I’ve never had a semi-automatic that didn’t soot up the case neck and shoulder. And, since we’re needing to lubricate the whole case prior to sizing, there’s no place for gunk. As said last time, case lube should not be a case cleaner!

There is also always going to be firing residue, if not on the case, it will be inside the case, and in there will also be primer residue, which is very abrasive.

Brass doesn’t have to be polished to be cleaned, which is to say that it doesn’t have to be shiny to be clean. Get down to the bare metal and that’s “clean.”

The question is How?

Not counting all the methods and means I’ve heard tell of, which number well over a dozen, the two common are either dry media or liquid media. Dry media is most commonly corncob or walnut, and run through a rotary- or (more popularly) vibratory-style appliance. There’s another I’ve been impressed with and that is the use of steel media, and more in a bit.

corncob media
Good old corn cob works just fine, but make sure you get all the residues off the cases.

Liquid means can revolve around detergent-type solutions and agitation, or the “sonic” cleaners.

General: Advantages to dry media are, well, that it’s dry! Not (as) much mess. Disadvantages exist, however. The main one is getting all the residual dust and particulate out of the cases. I caution against using any additional abrasive additives to the dry media because what doesn’t get cleaned away will, not can, accompany a bullet down a barrel. Advantages to wet media are that it can do a thorough job of cleaning, no doubt. It also doesn’t leave any residue. But! It’s wet! And that means the cases need dried thoroughly prior to reuse. There are specialty appliances that can do it, but a cookie sheet in an oven set on “low” does the trick too.

hornady case cleaner
Hornady Sonic Case Cleaner

Back to the steel: That’s why I like this method. Dry, no residue. It in no way hurts the cases, and works pretty quickly.

steel case cleaner
A newer dry media is steel. It works well and leaves nothing behind. This magnet is how you separate media from cases. This one is from Frankford Arsenal

No media lasts forever. Corncob, especially, should be routinely discarded and the appliance cleaned out to avoid any resident grit mingling with the media particles. Much as in the same way gold panning works, heavier junk can settle to the bottom of the bowl. Tumbling media, by the way, doesn’t really wear out: it just gets crudded up.

Take steps post-cleaning to ensure that residues are gone, and also that primer pockets are free of particles. Some use compressed air to blow out the case inside, and others go as far as to rinse and dry.

Speaking of primer pockets! I very strongly suggest decapping prior to cleaning. That way the pocket will, indeed, be cleaned. This doesn’t take much time and requires only an inexpensive station as shown nearby.

decaping die
I strongly recommend decapping primers prior to cleaning. A setup like this doesn’t cost much, and the operation is pretty painless.

Additional steps? There are some long-used steps taken especially by precision shooters, such as brushing the inside of case necks, and also using a polishing cloth to thoroughly clean the case neck, case shoulder area, and separate attention paid to the pimer pocket. But. These steps originated with Benchrest competitors and the reason is because I never met one yet who uses the short of cleaning apparatus “we” use. Never a tumbler! Their cases never hit the ground either. Nothing more than a thorough run through the volume-cleaning media of your choice should be needed, and the primer pocket cleaner should likewise be unnecessary if you take the advice of cleaning deprimed cases.

Honestly, it’s better, and I say best, if the case cleaning media leaves no residues. That’s where dry steel media and the liquid cleaners come in.

Back to the basics: Clean is clean. “Nothing but brass” is “clean.” Polished and gleaming cases are not necessarily better, and matter not a whit to performance.

One last: my favorite case cleaning “story” ever. Middleton Tompkins, many-time Highpower Rifle national champion, showed me his case cleaning method on a visit. Mid (and his wife, dominant Long Range Rifle winner, Nancy) go well beyond “high volume” in their needs for clean cases. To that end, Mid purchased a small commercial cement mixer into which he dumped pounds of BBs and a solution of Joy dishwashing soap and water (later rinsed and drained and dried). Now, that’s a high-volume case cleaner!

Check out Midsouth products HERE

And decapping DIES!

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