Tag Archives: Top-Grade Ammo

RELOADERS CORNER: When You Can’t Always Get What You Want

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And here’s hoping that, if you try sometimes, you get what you need. Sorry Mick. READ MORE

weigh brass

Glen Zediker

Yet one mo time: the topic for Reloaders Corner comes from recent letters on a topic, and this time it’s brass. Specifically, some were asking me about this and that such and such brands of brass that I’d had no direct experience with. The reason for the question was because my long-standing and well-known in-print recommendations had, for these folks, just not been possible to find. They were, by the way, looking for “good” brass, which can mean different things, but mostly new cases that were going to be consistent and had nothing that wouldn’t recommend them, if that made sense. If it didn’t, it means that the cases weren’t unusually hard or soft, or expensive, or, generally, exhibiting low or quirky quality.

These were competitive shooters, NRA High Power Rifle, by they way.

Anyone who’s read much from me on this topic knows I’m partial to American-made cases, WW in particular, and also (now) Nosler. Nosler isn’t cheap. You would also know that I am not a fan of European brands. I have used and continue to use a good deal of Lapua because I have a good deal of it, but it tends to be virtually perfect in dimension but soft in composition. And, gas gun or not, I do not like soft brass.

For this next to be as helpful as I’d hope it might be, the circumstance is this: We are going to try a few before we commit. We’re first going to buy a box before we get a case.

So after opening a container of new brass, how do you know “what you’ve got”? Have to find some way to measure it, then measure it, and start quantifying its quality or suitability. There are a few different checks myself and others make that provide numbers we can use to represent consistency. For the most part, and this will likely get the most support in agreement from others reading this now, case wall thickness consistency might well trump other checks that can be made. Of course (of course) there are tools that make this job — measuring wall thickness at 4 points around a case neck — easier and faster. Related but not exactly the same thing is running the new cases through a concentricity fixture (a “spinner”) that will show how much runout a case neck has. To make that truly reliably viable, though, all the cases much first be sized to round out the case neck cyclinder. That might not be such a chore, though, because in fact all those cases are going to need sized before they can be used. Otherwise, and this takes only a quick look to know, new case mouths are usually bent up and not nearly ready to accept a bullet.

There’s another way. Weigh them! Weigh them all. After a few tries and a few notes, you’ll get an idea of what represents the higher, lower weight range. Moving them into piles, a pattern, I guess we could call it, shows up. As with any segregation, the tolerance you’re setting determines on how many piles, but I suggest and try to keep it to three. Separation increments that are realistic and influential for case weight segregation varies on the physical size of the case and, of course, the tickiness of the operator. Again, though, if you weigh 100 cases and you have your numbers and your piles, you’ll start to see how both your criteria and your test pieces are relating. If your piles have cases that are under 1.0 grain difference each, meaning less than 3.0 grains total weight variance, that’s good! Really good. There are other surfaces (case rim for instance) where a little more or less material here and there contribute to the weight.

weigh cases
Weighing is going to be a little faster check especially when there’s a good number of cases in the mix. A good electronic scale makes it way on easier.

Weight is not (not nearly) an indicator of case wall thickness consistency. Well, or if it is, that’s sho not what the scale is directly showing you. It’s also not a direct indication of case volume, or of anything else for that matter! It is only showing a weight on each case. However! Over almost a half century messing with all this, I can tell you that — for some reason — it does without a doubt matter! It may only be some sort of clue to the “overall” quality of manufacture, I honestly don’t know.

I suggest it as an alternative to more “direct” means to gauge case quality just because everyone has a scale and initial weight readings are fairly fast and decidedly easy to take.

Now. Read just a little on this on the interweb and you’ll see weight segregation is most often discounted heavily as a viable criteria. As with much of what else you’ll read on the interweb it tends to be posted by folks who are long on opinion and short on resume. Right. They know it all but don’t actually go out and win anything.

weigh cases
Don’t confuse segregation means with segregration criteria. Case weight is not the same as wall thickness. Sorting by weight says you found the cases that weighted more nearly the same. They will, I assure you, shoot better than employing no segregation means.

One last, speaking of folks with impressive resumes, I know a good number of shooters on the U.S. Palma Team. These folks are all big into weight segregation. Since “real” Palma is fired with drawn ammo, the proven best way to find out which rounds in a box are going to shoot the closest together is simply to weigh all the loaded rounds and separate them by weight. That’s proven to do better than any other means for measure. It honestly does work for cases too.

The preceding is a adapted from information contained in Glen’s newest book America’s Gun: The Practical AR15. Available at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Factory Ammo

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Factory ammo is a fact of firearms life. How does it relate to us, as handloaders, and, how do we relate to it? READ MORE

factory ammo
Trying a boxfull of a few different ideas might help settle on what ends up being handloaded. There’s a lot out there to try.

Glen Zediker

I’ve long been an ammo snob because of my focus on target sports, and on the creation of ammo for same (a focus both for myself and for my published materials). If you’re building ammo to stake a score on then it has to be the best, it has to be custom, and that is a substantial investment in a lot of time and tools. And testing. Testing testing testing.

I’m now shooting more factory-made rounds than ever, and one reason is because of I’m doing a lot more work with more varied firearms. For me, handloading is a serious step up, not a casual step in. I don’t load for several of the different guns I have because of that. My son, Charlie, has been doing a good deal of published reviews, for instance, and neither of us is about to set up a station just to test a firearm chambered in anything we don’t already load for.

factory ammo
I keep this sort of thing on hand, and I also use the “better” grade of mil-spec for use in my guns. Hornady Frontier works well.

factory ammo

I also have come to accept that it may be a more fair test of a gun to run ready-made through it, but only because that is how it’s usually done: get a gun, get a few boxes of ammo, go to the range, and see what you have. I have every confidence that, given enough of that time and testing, I can make any rifle out there shoot better with a handload — I’ve seen that over and over and over again. But, I say factory ammo is a fair test because overall and after enough different tests with different guns there will be a pattern develop reflecting ammo quality. There are, therefore, decided performance tendencies I’ve seen in factory ammo, and, as with many things that have, at a base level, cost as a variable — it’s predictable.

“Premium” factory ammo shoots better! Of course it does. That’s assembled with, mostly, a quality bullet. For rifles it’s the barrel, for ammo it’s the bullet that matters most. So, if you’re wanting to see how well your new gun can shoot, choose a box of factory ammo that’s got the better bullet. That also gives you the chance to get started assembling a component list when you spool up the press to make your own for it. If you doubt that, ask any old NRA High Power Rifle shooter about “Mex-Match.” And, since I’m handy, I’ll tell you! Pull the bullet from a mil-spec load and replace it with a commercial match-grade bullet of a suitable weight. Groups shrink 50-60%.

The Value Of Factory Ammo
Are there times when factory is prefereable to custom?

Yes. At least, maybe.

factory ammo
This is what sits in my magazines that sit in or near my guns kept at the ready. I don’t bust clods with it. I don’t handload NATO-spec.

I keep factory ammo in my “ready mags.” That might surprise some. Yes, of course I “trust” my handloads. Usually, though, I won’t be shooting a lot of whatever is loaded into my house gun, and that’s all about bullets. I’ll shoot a ton of handloaded rounds through my main carbine, but not with the bullet I want being there if needed.

On that topic: it is the bullet options that factory ammo provides that can give it an edge over a routine-use handload. For instance, some of the “specialty” defensive or hunting factory recipes use bullets that often aren’t even available otherwise (or not readily). Or, and as said, it’s a better value all-around to get a few boxes of what you have chosen to represent best fulfillment of needs, get a zero with some, and then keep the rest at the ready, than it is to load them yourself. That requires routine load recipe testing, which requires purchase of more bullets, maybe different propellants, and so on.

Plus, since most are treated to sealant or at the least little to no contact with humans, there’s less chance of “stiction,” which can and will happen. (That’s when the bullet “freezes” in the case neck, and it raises pressure.) I’ve seen it, and it’s from plain corrosion, which is fueled mostly from handling the components. I’ve had it turn up in rounds loaded for no more than a year (and they popped a few primers). Some use latex gloves, and I started up that after this experience.

Specifics
First I apologize for this short list because there’s a lottamo out there. I only feel right, right now, about telling you what I have used that I really like.

Of the factory ammo I’ve shot, and this is across a range of cartridges, the Hornady line has overall been the most impressive. That’s for handguns and rifles. Hornady has a wide range of specialized loads (specialized bullets) that are well thought out, and, by my experience, well constructed. Stuff shoots well! For instance, their lower-cost “mil-spec” simply shoots better than others similar I’ve tried. Likewise, for hunting, defense, and targets, there will very likely be a load that’s been well-proven. Again, it’s usually the bullet that’s the difference. I shot a lot of good scores with Hornady bullets in my handloads, and some of their designs for impact effectiveness have proven themselves indeed effective.

I also like Nosler. It’s not cheap. Neither are the bullets or brass used in it! Nosler has been my go-to for .223 Rem. brass for a good while. Its quality is very good and it’s ready to load right out of the box, and it’s tough enough. I switched to Nolser match bullets also. I mostly got to shooting Nosler factory ammo when I got my 22 Nosler. Hornady has a wider selection for different needs, but my experience has been that I haven’t found anything that beats Nosler on-target. And I get to keep the cases!

I’m leaving a lot of makers out. Clearly, there is good and not good factory-loaded ammo. Those I know with a lot more rounds downrange from freshly-factory-sealed containers have good things to say about Federal Premium, and often favor Black Hills, and also agree with me about Hornady and Nolser.

Variety
There are a lot (a lot a lot) of options in bullets especially for .300 Blackout, for instance. The Blackout is that much more variable because of super- and subsonic.

factory ammo
Those specializing in specialized ammo often have more than one take on a load concept. Here are two subsonic developments from Hornady: a little heavier and a little lighter.

The .223 Rem. range, along with other popular cartridges, includes the “target” use loadings. Some are pretty good. However! I honestly think there’s a tad amount, to a lot, of kidding the self to think it will be better than what you can load for yourself. If you want to really find out how well your gun shoots, getchaseff to the loading bench.

As suggested, it might be wise to try a few factory loads in a new gun before making the investment in choosing components for your handloaded ammo to come.

The preceding is a adapted from information contained in from Glen’s newest book America’s Gun: The Practical AR15. Available at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.

RELOADERS CORNER: Press Tricks, Linkage

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Reloading press designs vary, and some offer advantages, if they’re needed. Read more about which, what, and why HERE

rcbs summit
RCBS Summit

Glen Zediker

This is the last (for now) look at reloading press designs and features, and it’s all about power — leverage and linkage.

The more leverage a press can generate the less input effort from us is required in performing an operation, especially a more challenging operation like reforming cartridge cases, but that’s got another side to it. A longer stroke, and a heavier mass to move, also means more exertion on each stroke, and more time spent case to case.

Since we don’t always know the ultimately most demanding operation we’ll call on a press to perform, my advice is to err on the “stronger” side, and also on the “longer” side. I prefer a press with a shorter handle stroke (and a shorter ram stroke) because it’s less tedious to operate — but that’s true only when the press ops are not taxing. Yes, I’ll explain more: when the duties are sizing small to medium sized commercial brass cases (like .223 Rem. up to .308 Win.), seating bullets, decapping, seating primers then excess press isn’t needed. But when it’s more taxing, like in the case reforming already mentioned, and also sizing once-fired military cases, or loading for a honker like .338 Lapua, a longer ram stroke and more leverage is most welcome.

reloading press design
Forster offers a shorter handle option for its CoAx because there are many who want to increase feel on some ops. The shorter handle reduces leverage.

I’ve been doing all this long enough to have collected more than one press, at more than one “size,” and I’ve used them all over a good many years. The one I use the most is on the smaller, shorter end of the press spectrum, and that is only because the most of the loading I do now is decidedly not taxing. But give me a Kroger sack full of Lake City 7.62 and my Forster CoAx or Harrell’s Sportsman is getting mounted up on the bench.

Speaking of effort, case lube is decidedly important in smoothing out taxing sizing ops. I prefer a petroleum-based lube, but that’s not meant to start an argument!

There are a few different takes on the best way to design linkage (the levering mechanism that powers the ram), including those that operate more or less upside down. I’ve not used them all but have, generally, found that handle length has the biggest influence on leverage.

reloading press design
A press that’s set up to “cam-over” really means it’s set up to flex. Any press with enough leverage can warp over on itself. This is a Harrells Sportsman: huge leverage.

Cam Over
Speaking of linkage… Some reloading presses are designed with eccentric linkage such that it’s possible to “cam” the ram. The concept involves circular motion and linear motion, meaning that when the ram traveling in a linear path reaches full extension, the linkage which is traveling in a circular path, can move through the 0-degree mark and go to a negative degree — like a crankshaft in an engine. To get a picture of this: As the handle is moved downward to elevate the ram, the ram reaches its maximum height just short of the very limit of its travel upward, and, at the last little bit, lowers. So when the handle is all the way through its arc, the press ram is sitting a little lower. This action, called “cam over,” has essentially increased “ummph” in the linkage, and it’s done that by making contact (plus) with the die.

I’m not a fan.

Now, any substantial press, whether it has eccentric linkage or not, can produce the effect of camming-over. A Forster Co-Ax, for instance, can just about crush a chrome car bumper and doesn’t have eccentric linkage. To set up that press, any press, to cam-over, turn the die a little (1/8 turn or so) downward beyond what provides full and flush contact with the shellholder when the ram is at its full height. Then, when the press handle is fully down, the additional pressure in the last bit of the handle stroke goes toward flexing the press. Simple as that, and that is what camming-over does: flex the press. And, again, that’s true whether it has eccentric linkage or not.

Don’t do it. Just don’t.

There’s no need to cam-over a press for a case-sizing operation. It creates unnecessary stress. Dies can get deformed and bent, carbide dies can break, and the press hisself can suffer, and even break. Some defend this practice by saying presses are designed to “take it,” but eventually there’s a penalty for taking any machine to its limits, continually.

The real deal is that it’s just not necessary! Using a cartridge case headspace gage to determine sizing die positioning to get the correct amount of case shoulder setback, it’s clear that sure should occur at a point short of full contact between the die bottom and the shellholder surfaces. But, and this is important, if it’s not then trying to push a case farther up into the die by crushing the shellholder against the die isn’t going to do much. Done is done. The flexing might, maybe (maybe), increase setback 0.001.

If your sizing die doesn’t adequately set back a case shoulder, then that die has to be modified by having material ground off its bottom.

Camming-over a press is a “feel-good” measure for some folks: there’s this satisfying “ka-thunk” at the limit of press handle stroke, and that lets a loader know that they gave it all it could get. I’ve also had some claim that the stress and flex brings “everything into perfect alignment.” No it doesn’t. Alignment in a press was determined by the maker, not pressure. If your press hain’t straight, bending it more won’t help.

Cam-over has its application in some bullet making operations, but those are not on-topic here.

reloading press design
Here’s eccentric linkage at work. On left is the maximum height attained by the ram; on right is the ram position at the full-limit stop on the press handle. It’s 0.020 inches on this press, a Harrells Turret.

More, And Some Is Good!
To find out if you have a “cammer” run the press ram fully up (press handle fully down) and thread a die in until it touches the shellholder. Try to move the handle back down. If it won’t budge, it’s got eccentric linkage. It won’t move because the ram is trying raise again. Back out the die until the handle moves and pulls the ram away. It’s at this point where “flush” contact with a die bottom will be. As long as the shellholder is not being contacted, presses with this sort of linkage have a smooth feel to them and do a little more positive job of sizing. In effect, the case gets sized twice (the ram elevates again just as the press handle is lowered). Linkage, either way, has zero effect on setting up a die because you measure what you get anyhow, and adjust the die accordingly, after you see what it is that you got.

The preceding is a adapted from information contained in from Glen’s books Top-Grade Ammo and 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: Press Tricks

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There are a few tricks and treats, and traps, in reloading press designs and associated pieces-parts. Shellholder first. KEEP READING

shellholder tricks
I honestly have had my best luck with Lee brand. Lee is inexpensive but I’ve yet to have a bad one, or one that wouldn’t work on different press brands (and I’m not alone in this opinion; a famous Benchrest competitor gave me the “Lee tip”). SEE IT HERE

Glen Zediker

Last couple of editions started a “press primer,” and this one should finish it off, at least for now.

Shell Holder Options
A correctly dimensioned and well machined shell holder is absolutely necessary.

Small differences in individual shellholders, and certainly in different brands of shellholders, mean that a shellholder change makes it necessary to check case sizing and bullet seating results again. Adjustment will likely be required. If a shellholder is a little bit thicker or thinner such as will influence the cartridge case “height,” then that’s transferred to the end result as measured in, for instances, cartridge case headspace and bullet seating depth.

That is exploited by some who produce shellholders with varying heights. These come in a set and have incremental differences that allow you to move a case up or down by swapping the shellholder. If you load for different rifles using the same die, and if these rifles all have a different ideal cartridge case headspace, for instance, then there can be less compromise without having to use a different sizing die.

shellholder tricks
Redding offers shellholders with varying heights to allow for small effective changes in sizing. Handy, for instance, for someone who loads for more than one rifle and wants to use the same die. There are 5 holders, each with 0.002-in. height difference. SEE IT HERE

Not all shell holders are interchangeable! They’re supposed to be, generally, but I’ve purchased different brands for use in differently branded presses, and they won’t fit.

Shellholder Tricks
Speaking of fit, check over a new shellholder for burrs and make sure it fits fully and freely into its slot in the press ram. And, speaking of its slot in the press ram, I have long been a believer in getting rid of the “spring clip” virually all presses use to secure the shellholder in place. The spring clip sits the shellholder askew atop the ram.

This clip can be removed. I use an o-ring as can be found at a real hardware store to fit into the outside slot formerly occupied by the clip. The elastic o-ring keeps the shellholder from coming slap out, but also takes a little (to a lot) of getting used to because the shellholder is free to spin and shift. It no longer snaps satisfyingly and firmly into place.

shellholder tricks
I’ve shown this before but it (really) works well to improve alignment odds. Canning the shellholder retaining clip so the part can sit flush and move a little helps it all self-center. This is a 7/8 o.d. x 11/16 i.d. x 3/32 thick o-ring that suits most press rams.

This arrangement lets the shellholder fit flat-flush against the ram and, very important, allows some “wiggle room” to let the shellholder float so the cartridge case can seek its own center as it enters the die.

I am absolutely convinced that a floating shellholder is a big help toward attaining concentricity in a round.

All mating parts surfaces have to have a tolerance. Lower (closer gaps) is better, but it can’t get too low or the dang parts won’t fit together. The way I see it, the more room for movement the bigger trick it is to get everything in alignment, if we want to lock it all in-line. Shellholders are fairly loose all around: the shellholder has to fit into the press ram slot and then the case has to fit into the shellholder and these fits are fairly free. Attempts to lock a shellholder in place, frankly, are contrary to best alignment, with maybe one exception.

On the other end of this, and this qualifies as a press “trick,” Forster has its own take on shellholder design. The Co-Ax shellholder uses what amounts to clamping jaws that are engineered to take up the slack in each individual case and lock it in dead alignment with the press ram. I’ve used Forster long enough and made enough gage checks, and shot enough high-x cleans with the resulting rounds produced on this machine, to tell you that it it, indeed, works. Years ago I tried an aftermarket add-on version of this concept produced by Quietics, makers of the original “inertia” bullet puller. It’s still available. Like the Forster, the same setting will work with a variety of cartridge sizes and that was the main draw to this “universal” shellholder.

shellholder tricks

shellholder tricks
Forster uses a proprietary system that gets a case centered with the ram and keeps it securely centered during a die op. Their Co-Ax design is pretty much a clamping shellholder. SEE IT HERE

Keep the shellholder and its slot clean. As often said, running a separate decapping station keeps the majority of gritty gunk off the main press parts.

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

 

REL0ADERS CORNER: Reloading Presses: Options

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A very “busy” reloader might consider a turret press to save on time. Read all about why HERE

turret press

Glen Zediker

Last time I wrote about the most basic and essential of all reloading tools: the single-stage press. They come in a few shapes and all sizes. Which you choose, as said, has much to do with how much leverage you need to perform the toughest operations you face on the loading bench.

Beyond size, however, there are other options in a press, and some might suit your needs best. The first that comes to mind is a turret. I’m a fan of turret presses, and for reasons that will be pointed out throughout this article.

turret press
This is a honker of a press and it’s well worth the cost. Lyman Brass-Smith. 8 station ops. And it’s actually on sale now at Midsouth so I have to back up on telling you turrets always cost more! CHECK IT OUT HERE

First, a turret is, pretty much, a single stage press that has more than one receptacle for threaded dies. Instead of threading in and out each separate die for each separate operation, just leave them in the tool head. The head on a turret press can be moved to center each die receptacle over the press ram.

turret press
Redding T-7 has been a long-time “standard” for a big turret, and that’s because it’s stout! Very heavy, very sturdy, and 7 stations. Cast iron. SEE IT HERE

turret press redding

Some turret presses are on the very heavy duty end of the press spectrum. Others not so much. A “big” Lyman, Redding, or RCBS turret press can hold enough dies to load different cartridges without changing heads, or dies. Lyman offers 8 holes, Redding 7, and RCBS has 6. If you’re using only a sizing and seating die, as might most for loading rifle rounds, you can handle more than two different cartridges without ever threading in or out a die. That, to me, is a valuable thing. The dies stay adjusted and, no doubt, either of those presses has more than plenty leverage to handle any and all sizing, reforming, and any other press ops.

Lock-N-Load AP Auto Progressive Press

Take a tour of all available reloading presses at Midsouth Shooters HERE.

The ultimate value in a turret, in my mind, is getting one that allows for straightforward tool head swaps. That way you can leave all the (adjusted) dies in the tool head and when it’s time to change cartridges, remove the head and replace it with another that also houses the necessary adjusted dies. My choice in turrets, therefore, runs on the smaller-bodied side of available options. I prefer to keep all the dies for one cartridge in one head. To that end, a 3 or 4 hole turret fits my bill. The most popular and easily available is from Lee, and I’ve used one of those for years for case forming ops. I put all the needed dies for a cartridge conversion — forming dies, trimming die — in the turret head and shuck away, moving from station to station as needed.

I have known folks who used a turret press pretty much as a “manual-automatic” progressive, and auto-indexing can be incorporated into a Lee. Crank the handle, move the turret head one hole, crank again, move the head again, and so on. That’s not my way to run one. A true progressive press is way on better if you’re looking to speed up the overall loading process. Again, turrets help us move faster because we don’t have to stop and re-up the tooling for each case operation.

turret press
The Lee Classic 4-Hole Turret has been around a while and I’ve used one for a while too. I like it fine. Heads are inexpensive and really fast to change out. I am not a fan of its auto-index, but that is easily “switched off.” SEE IT HERE

I have found that running a 4-hole turret for my personal needs in loading my NRA High Power Rifle Service Rifle ammo (for an AR15) was the without-a-doubt best way to get me through the tooling tickiness I had developed in manufacturing those rounds, which was almost always done the night before. For that rifle and that venue, I used two different bullets and two different case neck dimensions (lighter constriction for the 600 yard load) so I ran a sizing die, which was set the same for all rounds; then an inside neck sizing mandrel to alter the case neck tension; then one seating die set for 77gr. magazine-length rounds and another set for 80gr bullets. That setup occupied the 4 holes I had available in my turret head. I saved a lot of time with this setup. The dies stayed put and therefore never a worry about consistency use to use. I did index-reference all the dies using a paint marker so I could see if anything had inadvertently rotated.

turret press harrells
This is my most-used press: Harrells 4-Hole Turret. This is a small-shop precision made machine and hain’t nearly cheap. It clamps just about anywhere and can be either a 2, 3, or 4 hole depending the head plate. SEE ONE HERE

Other ideas on making full use of a turret include incorporating one of the threaded-type priming tools (such as Lee Ram Prime) or even a powder meter station (using a meter with 7/8-14 threads). Clearly, turrets are great for pistol shooters who need sizing, expanding, seating, and often a separate crimping station.

I honestly am really tempted to wholesale recommend a turret press to anyone who’s got to deal with any or certainly many of the benefit potentials mentioned. Loading for more than one cartridge, needing more than a couple of dies, and so on. Only trick is that a turret press is going to cost more money. Making a play on the old hot-rodder adage: Speed costs money, so how fast do you want to spend? Time also can cost money, and how much do you want to save? If time is more valuable to you, by all means get a turret.

turret press

And, last, even though it’s always important to keep any press cleaned and lubed, it’s even more so with a turret.

The preceding is a adapted from information contained in from Glen’s books Top-Grade Ammo and 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: Learning To Load Again, pt. 1

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Whether you’ve been loading for 50 years or 5 minutes, it’s a good idea to revist the basics from time to time. READ MORE

Glen Zediker

[I know that my readership for this column has a pretty broad range of experience, and, therefore, a broad topic-interest range, plus expectations on what I hope to communicate or relay. I’ve been asked both to go into more details about specialized processes and procedures and also to stick more with broader topics, and keep it simple. Can’t win on all topics each edition with everyone, so I do my best to mix it up. This one is leaning heavily toward simple, but, as always, I hope there’s something to absorb, or at least think about.]

A few issues back I wrote about how I had been teaching my son how to reload. After doing all this for so long (I started when I was 15) and likewise going fairly far “into it” over many years, the basics are pretty much ingrained in me. That doesn’t mean, in no way, that I don’t have to check myself or remind myself (which usually comes after the checks) to follow the procedures and the rules to the letter.

calipers

Short digression into the backstory on this project: Charlie wanted to reload for the very same reasons I got my start in this process. For his 18th birthday, he became the proud owner of a retro-replica “M16A1.” This was his choice, of all the choices he could have made, because it’s an “original.” Of course, his is a semi-auto with only two selector stops, but otherwise is straight from the late 1960s. He found out right quick like and in a hurry that it was a hungry gun, and, as an equally hungry shooter, the need for feed exceeded the factory ammo budget in short order.

Back to the project: So when I set out to teach Charlie how to produce his own ammunition, I sat back a while (a good long while, and longer than I imagined) and ran it all through my mind and realized that I knew so much about it that it was hard to know where to start. Now! That’s not some sort of brag, just the facts, and the same would be said for most of you reading this. I knew so much about it because there’s so much to know! Handloading is a multi-faceted task, made up of many (many) tasks, all and each important.

So where did I start? With a breakdown of the cartridge itself. Which components did what, when, and how. And, of course, the long list of “always, only, and never.” This article isn’t about a step by step on how to load, but in going over the separate points, point by point, some things stood out as more or less easy to communicate, and more or less easy for my son to grasp (related no doubt).
I know that my readership for this column has a pretty broad range of experience, and, therefore, a broad topic-interest range, plus expectations on what I hope to communicate or relay. I’ve been asked both to go into more details about specialized processes and procedures and also to stick more with broader topics, and keep it simple. Can’t win on all topics each edition with everyone, so I do my best to mix it up. This one is leaning heavily toward simple, but, as always, I hope there’s something to absorb, or at least think about.

Setting up the tooling to get started on our project, I had Charlie do it all himself. One of the very first points to pass heading up the learning curve was learning to measure.

Depending on someone’s background and specific experience, something like operating a measuring tool can range from old-hat to no-clue.

calipers
A caliper is an essential, absolute must-have tool for reloading. It doesn’t have to be the best to be entirely good enough. We need to measure to 0.001, so get one that does that. Make sure it’s steel so it will hold up.

Honestly, the only measuring tool you really need to handload is a dial caliper. You’ll use this to measure cartridge case overall length, over cartridge length, case neck outside diameter, and also to check the results of a few difference gages, like a cartridge case headspace gage.

That, therefore, was the first tool he learned how to operate.

Here’s a question I had to answer, and it’s a good question to be answered especially for those unfamiliar with measuring tools. That question is how “hard” to push on the tool to take a read. How to know that the reading is correct.

It’s full and flush contact, but not force. It’s as if the part being measured was making the same contact as if it were sitting on the benchtop: full, flush contact but no pressure. In measuring some of the things we measure, like bullets, and considering the increments of the reads, pressure against the tool can influence the read if the material surface is actually compressed. That’s from flex. I usually very gently wiggle the part being measured to feel if the contact with the tool is flush, that there’s no skew involved. There is, no doubt, some feel involved in measuring. I know some say that there should be pressure to get an accurate reading, and I would agree if we’re measuring materials that are harder than bullet jackets and brass cases. But again, it is decidedly possible to flex and actually displace soft materials if there’s too much pressure applied to snug down caliper jaws or mic heads. Get a feel for flush, the point just when the movement stops firmly and fully.

calipers
Measuring correctly and accurately involves feel, which comes from experience. Contact must be flush but not flexed!

Caliper Quality
More about the tool itself: My experience has been that there’s really no difference in the at-hand accuracy of more expensive measuring tools, especially a caliper.

calipers
Tips: Don’t store the caliper with the jaws fully closed. Keep it clean. Keep it cased. Make sure to zero the caliper (dial or digital) before every session.

Digital is great, but not at all necessary. Digital is not more accurate or precise, it’s just “easier.” As with a scale, it really depends on how much you plan on using it. If you’re going to measure everything, then digital is better because it’s faster to read — there’s no dial-mark interpretation involved. If you only want to check neck diameters and case lengths when you’re setting up your tools, then a dial-style is entirely adequate.

Get steel! Something that reads to 0.001 inches.

There are several industry-branded dial and digital calipers from Lyman, Hornady, RCBS, MEC, and more, available here at Midsouth. These range from $30-50 or so. They are all good, and they all are entirely adequate. If you want to spend up and get better, Mitutoyo and Starrett are the brands to know. Those easily double that cost.

These tools do wear. All will wear. Better tools wear less for a longer time. Conversations with folks who use calipers, along with other measuring tools, not only daily, but continuously during a day, has taught me to be confident in that statement.

Calipers can measure other things, but there are specialty tools that replace them for specific tasks. For instance, yes, it’s possible to measure case wall thickness with a caliper, but it’s not very precise.

calipers
Hopefully you’ll be able to use your caliper to measure groups like these. It’s really the only tool you need to get them.

Check out Midsouth tools HERE

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: Extending Barrel Life

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Good barrels aren’t cheap. Here are a few ideas on getting the most accurate life from your investment. READ MORE

barrel life
Flat-base bullets obturate more quickly than boat-tails, and that reduces some of the flame-cutting effect from propellant gases.

Glen Zediker

Rifle barrel chamber throat erosion was the topic last time, and mostly its causes and the effects. Short retake: The barrel “throat” is the area directly ahead of the case neck area cut into the chamber. This is the area that receives the majority of the “flame cutting” created by burning propellant gases. When a barrel “quits” it’s from deterioration in the throat. The greatest enemy to sustained accuracy is the steel surface roughness.

The throat is also advancing, getting longer, as the steel deteriorates; it’s wearing in little bit of a cone shape. The gap, or “jump,” the bullet has to cross before engaging the lands or rifling therefore is increasing, and also plays its part in poorer on-target performance. Last time I talked about using a gage to measure and record the actual amount of this increased gap. One way to preserve more consistent accuracy, which means not only group size on target but also shot impact locations (zero) is to adjust seating depth for the lengthening throat.

A chronograph also comes into this picture.

barrel life
Use this gage, along with a chronograph, to adjust the load to maintain the “same” as the barrel throat erodes. More propellant, longer cartridge length to maintain jump. GET ONE HERE

Routinely chronographing your load will show that velocity drops as the round count increases. Since the throat is getting longer (and slightly larger) there is more and more room for expanding gases. Pressure will, therefore, be lower and, along with that, so will bullet velocity.

Increasing the propellant charge to maintain original velocity is a tactic used by a good many good NRA High Power Rifle shooters. Bumping the charge in this way to maintain velocity is a safe and sound practice, by the way. I mention that because, over enough rounds, you might be surprised just how much change is needed. Middleton Tompkins, one of the true Jedi Masters of competitive rifle shooting, used this — propellant charge level increase — above all else to determine when a barrel was “done.” On a .308 Win., for example, when Mid was +2.0 grains to keep the same speed, that barrel became a tomato stake.

Moving the bullet forward to maintain the same amount of bullet jump, or distance to the lands somewhat offsets the result of reduced pressure and velocity as the throat lengthens, but, overall, and if it’s done in conjunction with bumping up the charge, both these tactics are a safe and sage help to preserve on-target performance for a few more rounds, maybe even a few hundred more rounds.

Either of these tactics, and certainly both together, requires a level of attention that many (like me) might not be willing to give. To actually see some reliably positive effect from maintaining velocity and jump consistency, you’ll need to make checks at least every 300 rounds. That’s a fair amount.

Another point I need to clarify is that moving the bullet out to maintain jump only matters to rounds that don’t have some magazine box overall length restriction. Otherwise, propellant charge for loads for rounds constructed with box restrictions can be wisely increased to maintain velocity, but the increased jump will take its toll on accuracy sooner than it would if jump could also be adjusted for.

Other Ideas
A few more ideas on keeping a barrel shooting better longer: Bullet choice can matter, if there’s a choice that can be made. Flat-base bullets will shoot better, longer in a wearing barrel. Trick is that when we need a boat-tail we usually need a boat-tail! Flat-base bullets “obturate” more quickly. Obturate means to “block,” and here it means to close a hole, which is a barrel bore, which means to seal it. The angled tail on a conventional boat-tail creates a “nozzle” effect intensifying the cutting effect. Flat-base will result in a longer barrel life, and, in the way I’m approaching it here, is that they also will extend the life of a barrel after erosion might otherwise have taken its toll. Erosion tends to, at least effectively, become exponential: the more it wears the faster it wears more. An obscure but well-proven boat-tail design does increase barrel life, and also usually shoots better though a worn throat, and that is a “rebated” boat-tail. This design has a 90-degree step down from the bullet body (shank) to the tail. It steps down before the boat-tail taper is formed. These obturate quickly. It is common for competitive shooters to switch from a routine boat-tail to a rebated design when accuracy starts to fall of. Sure enough, the rebated design brings it back for a couple hundred more rounds.

barrel life
Uncommon design, but very effective, all around: DTAC 6mm 115gr RBT (rebated boat-tail). The step-down to the tail mimics a flat-base in its capacity to seal the bore. It’s a sort of “best of both worlds” design.

A Welcome Set Back
Another common way to (really) extend barrel life for a bolt gun is to “set-back” the barrel. Pull the barrel, cut some off its back end, and then re-chamber and re-thread, and re-install. New barrel! Well, sort of. Given that there’s no significant wear on the barrel interior elsewhere, overwriting throat erosion does put that barrel almost back to where it started, except being overall shorter. That tactic works very well for chromemoly barrels but not so well for stainless steel. The difference is in the “machine-ability” of each steel. It is possible to set back a stainless barrel, but it’s difficult to then get a “chatterless” cut when the reamer engages. A little more usually needs to be removed to get good results with stainless, and this, of course, is making the barrel overall that much shorter. You have to plan ahead for a set-back, and that means including enough extra length to compromise. Usually it takes a minimum of 1 inch to get a worthwhile result with chromemoly.

In case you’re wondering, coated bullets don’t have any influence on throat erosion, but they do seem to shoot better through a roughening throat. Boron-nitride is the only bullet coating I will recommend.

barrel life
And make sure you’re not eroding your own barrel! Get a rod guide and a good rod and keep the rod clean! A log of throat damage can result otherwise.

One last for the semi-auto shooters. Throat erosion is also creating more volume to dissipate more pressure, which reduces the pressure that gets into the gas system. If you’re running an adjustable gas block, it’s liable to need readjustment, or, as also suggested, altering the propellant charge should likewise overcome any issues. This is one reason that savvy builders tended to increase gas port diameter on an NRA Service Rifle, for instance, to ensure good function after a fairly high number of rounds had done downrange.

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: Barrel Throat Erosion

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How long does a barrel last? About 5 seconds. KEEP READING

throat erosion
Well, it’s hotter than this, but it’s flame cutting over time and distance, and hotter for longer is the issue.

Glen Zediker

As is by now common enough in this column I write, ideas for topics very often come from questions that are emailed to me. As always, I figure that if someone has a question they want answered, then others might also like to know the answer. This question was about barrel life and, specifically, this fellow had been reading some materials on the interweb posted by some misinformed folks on the topic of bullet bearing area and its influence on barrel life: “Is it true that using 110 gr. vs. a 150 gr. .308 bullet will extend barrel life because of its reduced bore contact?”

NO. Not because of that.

However! The answer is also YES, but here’s why…

Wear in a barrel is virtually all due to throat erosion. The throat is the area in a barrel that extends from the case neck area in the chamber to maybe 4 inches farther forward. Erosion is the result of flame-cutting, which is hot gas from propellant consumption eating into the surface of the barrel steel. Same as a torch. There is very little wear caused from passage of the bullet through the bore, from the “sides” of the bullet, from friction or abrasion. The eroding flame cutting is at or near the base of the bullet.

When the propellant is consumed and creates the flame, the burn is most intense closer to the cartridge case neck. There are a few influences respecting more or less effect from this flame cutting. Primarily, it’s bullet weight. Time is now the main factor in the effect of the flame cutting. Slower acceleration means a longer time for the more intense flame to do its damage.

The slower the bullet starts, and the slower it moves, the more flame cuts in a smaller area for a longer time.

Bullet bearing area, therefore, has an influence on erosion, but that’s because it relates to acceleration — greater area, more drag, slower to move.

The amount of propellant, and the propellant nature, do also influence rate of erosion. Some assume that since there’s more propellant behind a lighter bullet that would create more erosion, and that’s true, but that is also not as great a factor as bullet weight. Other things equal, clearly, more propellant is going to cut steel more than less propellant. A “lighter” load will have a decidedly good effect on barrel life.

throat erosion
It’s heavier bullets that have the most influence on shortening barrel life.

Heavier bullets, without a doubt, are a greater influence than any other single factor. “We” (NRA High Power Rifle shooters) always supposed that it was the number of rapid-fire strings we ran that ate up barrels the most, but that was until we started using heavier bullets and found out in short order that our barrels weren’t lasting as long. That was moving from a 70gr. to an 80gr. bullet.

The “nature” of propellant is a loose reference to the individual flame temperatures associated with different ones. There have been some claims of greater barrel life from various propellants, but, generally, a double-base will produce higher flame temperature.

Even barrel twist rate plays a role, and, again, it’s related to resistance to movement — slower start in acceleration. Same goes for coated bullets: they have less resistance and move farther sooner, reducing the flame effect just a little. And, folks, it’s always “just a little.” It adds up though.

There are bullet design factors that influence erosion. A steady diet of flat-base bullets will extend barrel life. There’s been a belief for years and years that boat-tail bullets increase the rate of erosion because of the way the angled area deflects-directs the flame. And that is true! However, it’s not a reason not to use boat-tails, just a statement. We use boat-tails because they fly better on down the pike, and, ultimately that’s a welcome trade for a few less rounds. An odd and uncommon, but available, design, the “rebated boat-tail” sort of splits the difference and will, indeed, shoot better longer (they also tend to shoot better after a barrel throat is near the end of its life).

The effects or influences of barrel throat erosion are numerous, but the one that hurts accuracy the most is the steel surface damage. It gets rough, and that abrades the bullet jacket. The throat area also gets longer, and that’s why it’s referred to as “pushing” the throat.

The roughness can’t much be done about. There are abrasive treatments out there and I’ve had good luck with them. Abrasive coated bullets run through after each few hundred rounds can help to smooth the roughness, but then these also contribute their share to accelerated wear. I guess then it’s not so much a long life issue, but a quality of life issue. I do use these on my competition rifles.

lnl gage
Use the Hornady LNL O.A.L. gage to record and then track barrel throat wear. This isn’t technically a “throat erosion gage,” which do exist, but I’ve found it an easy and reliable way to keep up with an advancing throat. As the seating depth gets longer, it’s indicating how far the throat is advancing. Get one HERE 

Keeping in mind that the throat lengthens as erosion continues, using something like the Hornady LNL tool shown often in these pages can let bullet seating depth that touches the lands serve as a pretty good gage to determine the progress of erosion. On my race guns, I’ll pull the barrel when it’s +0.150 greater than it was new. Some say that’s excessively soon, and a commonly given figure from others in my circle is +0.250. One reason I pull sooner is that I notice a fall-off in accuracy sooner than that since I’m bound by a box magazine length for my overall cartridge length for magazine-fed rounds with shorter bullets, and I’m already starting with a fairly long throat (“Wylde” chamber cut). And another is because gas port erosion is having some effect on the bullet also by that number of rounds. Which now leads into the “big” question.

So, then, how long does a barrel last? Get out a calculator and multiply how many rounds you get before pulling a barrel by how long each bullet is in the barrel and barrels don’t really last very long at all! At full burn, maybe 4-6 seconds, some less, or a little more.

Another misgiven “fact” I see running rampant is associated with comparing stainless steel to chromemoly steel barrels for longevity. Stainless steel barrels will, yes, shoot their best for more rounds, but, chromemoly will shoot better for an overall longer time. Lemmeesplain: the difference is in the nature of the flame cutting effect on these two steels. Stainless tends to form cracks, looking like a dried up lakebed, while chromemoly tends to just get rough, like sandpaper. The cracks provide a little smoother surface for the bullet to run on (until they turn into something tantamount to a cheese grater). The thing is that when stainless stops shooting well it stops just like that. So, stainless will go another 10 to 15 percent more x-ring rounds, but chromemoly is liable to stay in the 10-ring at least that much longer than stainless steel.

throat erosion
Stainless steel barrels keep their “gilt-edge” accuracy for about 15% more rounds, but hit the wall head-on and in a big way when they reach their limit. Chromemoly steel tends to open up groups sooner, but also maintains “decent” accuracy for a longer time, by my experience — the groups open more slowly.

Do barrel coatings have an effect? Some. A little. I’ve yet to see one that made a significant difference, or at least commensurate with its extra expense. Chrome-lined barrels do, yes, tend to last longer (harder surface), but they also tend not to shoot as well, ever. Steel hardness factors, but most match barrels are made from pretty much the same stuff.

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: Making Space

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Some reloading ops don’t have to be done in a full-blown shop. Here are a few ideas when space, and comfort, are both at a premium. READ MORE

home reloading
There are stand-alone and then set-aside mounting solutions for folks who don’t have shop space. This is from Lee and available here at Midsouth.

Glen Zediker

I recently, at his request, took on the task of teaching one son to reload for his AR15. It was in the middle of the winter and my shop/studio area was pretty much closed down for the season. But he persisted, and it was also just the sort of thing I needed to shift gears and give myself a test of what I truly do know that I set out to share with you all each edition. I say that sort of humorously, but not really! Getting back to the basics, starting from the start, is a great idea. I recollect from experiences in what amounted to another life for me (I used to be a PGA Member), the great golf champion Jack Nicklaus would return to his original teacher, Jack Grout, at the start of each PGA Tour season and say: “I’m Jack Nicklaus. I’ve been thinking about taking up golf. Can you show me how to hold the club?”

So the immediate challenge for me was to make this learning experience worthwhile and also comfortable! And easy given the busy schedules we both have.

Many of us have well thought out and lavishly equipped reloading work spaces, and, others, not so much. All during the many many years I’ve been reloading, I’ve lived in apartments, moved to new locations, and, either way, didn’t always have access to the well-lit and sturdily-constructed “loading bench.”

I’ve made do, and, looking back, I don’t think I ever missed a point as a result.

Tricks and Tips
C-clamps are wonderful allies! Mounting many tools doesn’t require direct bench-top fastening. For years, even with a full-scale shop to stretch out in, I have been a fan of mounting tools on “platforms” and then clamping that to the bench when needed. I have a penchant for efficiency in loading and a big part of satisfying that is being able to relocate tools. In other words, I don’t want to have a trimmer, priming tool, and so on and on, all mounted in a (long) row along my benchtop. I want to be able to locate them where I want them, when I need them.

home reloading
A little creativity can mount most tools for easy location-relocation. Drill straight! That matters.
home reloading
Here’s a Forster trimmer mounted to that wood piece that can pretty much clamp anywhere.

Get to the hardware store and invest in some wood pieces, fastener-fixtures, and hex-head-screws. Take a priming tool, for instance, and mount it to the wood and then clamp that to the benchtop (or any suitable surface, anywhere) and commence to using it. Simple!

home reloading
This is an easy way to mount a quickly removable tool, like this small Lee press.

I’ve also had good success locating the tool mount spots I prefer for various appliances on my benchtop and then using the hex-head screws to attach the tools via installed threaded fastener receptacles when I want to use them.

home reloading
Built-in clamps are where it’s at. I’m a big fan of Harrell’s Precision tools and the omnipresent clamp is one small reason why.

I’ve even taken to doing that in mounting big tools. The bench where I load ammo is also the same bench where I build guns, or they share common area. After getting tired of bolting and unbolting vises and presses, I mounted each to a 2X12 piece of wood and affix either to the benchtop using a couple of honking c-clamps. As long as there’s enough area to get a good clamp down and enough surface area to sit the bench, I cannot tell the difference.

Now, when it comes to some higher weight and higher leverage tools, like presses, some of what you can get away with, in a way of looking at it, has a lot to do with how sturdy the base platform needs to be. Sizing .223 Rem.? Not much stress. Bigger cases, more stubborn ops, might need more substantial grounding.

For us, a combination of c-clamps and factory-mounted clamps on some of our meters and presses meant we could set up alongside each other at, believe it or not, our kitchen table and load in comfort, and easy access to a refrigerator!

home reloading
An assortment of fasteners: t-bolts and barrel screws from a hardware store, along with a c-clamp.

There are also some handy ready-made bases for loading available HERE at Midsouth.

Point is, if you don’t have access to a conventional bench, work area, or you want to prime cases while you’re watching television with your friends or family, there’s a solution. It just takes a little creativity.

Just pay attention to the loading!

home reloading
Here’s son Charlie ready to learn how to set up a sizing die… In the comfort of our kitchen, in the middle of the winter. Ammo loaded here shoots just as well as that done in the shop.

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: Standard Deviation

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Before getting into improving bullet velocity Standard Deviation, it’s first necessary to understand what it is, and what it isn’t. KEEP READING

chronograph screen

Glen Zediker

I got started on this topic last time, and kind of came in through the side door. Quick backstory: the topic was how to start on solving unsuitably high shot-to-shot velocity inconsistencies. This time we’ll start at the other end of this, and that is taking steps to improve already suitable velocity deviation figures.

Clearly, the first step in getting involved in velocity studies is getting the velocities to study. Of course, that means you need a chronograph. Midsouth Shooters has a selection and there’s a direct link in this article.

Virtually all chronographs are going to be accurate. A well-known manufacturer of shooting-industry electronics once told me that unless a chronograph displays a reading that’s just crazy unrealistic, you can rely on the number. The reason is that the current state of circuitry is pretty well understood and heavily shared. Pay attention, though, to setting up the device according to suggestions in the instructions that will accompany the new chronograph. The more recent Doppler-radar-based units are not technically chronographs, but they function as such. The advantages to those are many! More in another article soon. For now, for here, what matters is getting some numbers.

labradar
Latest and greatest, in my mind, advancement in data collection is doppler radar based units, like this from LabRadar. Easy to use, and not finicky about sunlight and setup.

Point of all that was this: You don’t have to spend up for the best to get a good chronograph. One of the price-point differences in chronographs is how much it will help work with the data it gathers. Most of us any more don’t have to do hands-on calculations. Me? All I want is a number. However, there are a good many that will record, calculate, and print.

magnetospeed
Barrel-mounted electro-magnetic chronographs like this one from MagnetoSpeed make it easy. I like being able to read speeds without all the setup, and not having to rely on a benchrest-type restriction. It stays on the rifle so can easily be used in the field. There are rail mounts available also.

Terms and Twists
Speaking of calculations, the most known and probably most used expressed calculation of collected velocity figures is Standard Deviation. SD suggests or reflects the anticipated consistency of bullet velocities (calculated from some number of recorded velocities). “Standard” reflects on a sort of an average of the rounds tested. I know saying “sort of” disturbs folks like my math-major son so here’s more: SD is the square root of the mean of the squares of the deviations.

Standard Deviation calculations did not originate from ballistic research. It’s from statistical analysis and can be applied to a huge number of topics, like population behavior. SD calculation forms a bell curve, familiar to anyone who ever had to take a dreaded Statistics class. The steeper and narrower the apex of the bell, the narrower the fluctuations were. But there’s always a bell to a bell curve and the greatest deviations from desired standard are reflected in this portion of the plot. Depending on the number of shots that went into the SD calculation, these deviations may be more or less notable than the SD figure suggests.

Calculating SD
If you have no electronic gadgetry to help: add up all the recorded velocities and divide them by the number of records to get a “mean.” Then subtract that mean value from each single velocity recorded to get a “deviation” from the mean. Then square each of those. Squaring them eliminates any negative numbers that might result from cancelling out and returning a “0.” Add the squares together and find the mean of the squares by dividing again by the number of numbers — minus 1 (divide by n -1; that eliminates a bias toward a misleadingly small result). Then find the square root of that and that’s the Standard Deviation figure, which is “a” Standard Deviation, by the way, not the Standard Deviation.

bell curve
This is a bell curve such as results from plotting an SD calculation, and is given here only an example of how the distribution, the “odds,” graph out.

Knowing a load’s SD allows us to estimate-anticipate how likely it is for “outliers” to show up as we’re shooting one round after another. Based on the distribution based on the curve, if we have an SD of 12, for instance, then a little better than 2 out of 3 shots will be at or closer to the mean than 12 feet per second (fps). The other shots will deviate farther: about 9 out of 10 will be 19 fps, or less, from the mean. 21 out of 22 will be 24 fps closer to the mean. Those numbers represent about 1.00, 1.65, and 2.00 standard deviations.

Now. All that may have ranged from really boring to somewhat helpful, to, at the least, I hope informative.

Mastery of SD calculation and understanding doesn’t necessarily mean smaller groups. It gives a way to, mostly and above all else, tell us, one, the potential of the ammo to deliver consistent elevation impacts, and, two, reflects on both how well we’re doing our job in assembling the ammo and the suitability of our component combination.

I honestly pay zero attention to SD. I go on two other terms, two other numbers. One is “range,” which is the lowest and highest speeds recorded in a session. The one that really matters to me, though, is “extreme spread.” That, misleading on the front end, is defined as the difference between this shot and the next shot, and then that shot and the next shot, and so on. Why? Because that’s how I shoot tournament rounds! This one, then another, and then another. A low extreme spread means that the accuracy of my judgment of my wind call has some support.

Depending on the number of shots and more, SD can be misleading because it gets a little smaller with greater amounts of input. Extreme spread doesn’t. I have yet to calculate an SD that put its single figure greater than my extreme spread records.

Lemmeesplain: The shot-to-shot routine is to fire a round. It’s either centered or not. If it’s not centered, calculate the amount of correction to get the next one to center. Put that on the sight. Fire again. If I know that there’s no more than 10 fps between those rounds, that’s no enough to account for (technically it can’t be accounted for with a 1/4-MOA sight) then it’s all on me, and if it’s all on me I know that the input I got from the last shot, applied to the next shot, will be telling. Was I right or wrong? It can’t be the ammo, folks. Then I know better whether the correction is true and correct.

Some might be thinking “what’s the difference?” and it’s small, and so are scoring lines.

A load that calculates to a low SD is not automatically going to group small, just because it has a low SD. Champion Benchrest competitors have told me that their best groups don’t always come with a low-SD load. But that does not apply to shooting greater distance! A bullet’s time of flight and speed loss are both so relatively small at 100 yards that any reasonable variation in bullet velocities (even a 20 SD) isn’t going to open a group, not even the miniscule clusters it takes to be competitive in that sport. On downrange, though, it really starts to matter.

For an example from my notes: Sierra 190gr .308 MatchKing, in a .308 Win. Its 2600 fps muzzle velocity becomes 2450 at 100 yards and 1750 at 600 yards (I rounded these numbers).

If we’re working with a horrid 100 fps muzzle velocity change, that means one bullet could lauch at 2550 and the next might hit 2650, in the extreme. The first drifts about 28 inches (let’s make it a constant full-value 10-mph wind again to keep it simple) and the faster one slides 26 inches. That’s not a huge deal. However! Drop — that is THE factor, and here’s where inconsistent velocities really hurt. With that 190, drop amount differences over a 100 fps range are about 3 times as great as drift amounts. This bullet at 2600 muzzle velocity hits 5-6 inches higher or lower for each 50 fps muzzle velocity difference. That is going to cost on target. And it gets way (way) worse at 1000 yards. Velocity-caused errors compound on top of “normal” group dispersion (which would be group size given perfect velocity consistency).

This 100 fps example is completely extreme, but half of that, or even a quarter of that, still blows up a score, or creates a miss on an important target.

That all led to this: What is a tolerable SD?

I say 12. There has been much (a huge amount) of calculation that led to that answer. But that’s what I say is the SD that “doesn’t matter” to accuracy. It’s more than I’ll accept for a tournament load, but for those I’m looking for an extreme spread less than 10 fps (the range might be higher, but now we’re just talking terms). More later…

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This article is adapted from Glen’s book, Handloading For Competition, available at Midsouth HERE. For more information on that and other books by Glen, visit ZedikerPublishing.com