Reloading problem? First make sure it’s not your tools… Here are a few things that can happen, and how to correct them.
Over years and years (and years) I’ve encountered a few factory-faulty sizing and seating dies, and associated pieces-parts. It’s not at all common, but it happens, or has happened, enough that I wanted to share a few stories as to what these problems come from, and how to identify (and correct) them.
As has been my norm here of late, yep: got a phone call from a fellow having problems with a new 28 Nosler. Took a while to get through this one… Turned out that the sizing die was the culprit. Wasn’t easy to sleuth but there’s a Zen tenet that paraphrases to this: If you’re not sure what something is, then carefully consider all the things that it is not; what’s left is the answer…
By the way, I’m not going to mention brand names for one good reason: I’ve seen or been presented with issues in dies from every major maker.
Sizing die problems I have either encountered first-hand or been witness to via my circle have most often been a full-length die that will not adequately set a case shoulder back where we want to take it. Conversely, it’s much more common to have a die that’s erring on the more extreme end of that, and erring toward “too much” sizing potential is logically a direction a die maker might take to accommodate more circumstances. Once the shellholder is making full and flush contact with the die bottom, that’s all she wrote. Continuing to turn the die body downward does nothing but stress the press and possibly damage the die. To get the case farther up into the die, either thin the shellholder top surface or grind the bottom of the die hisself. Neither are hand-tool operations! Get to a local gunsmith or machinist.
Look at a hair from your head and that’s ballpark 0.004-0.006 inches. It doesn’t take much at all to make the difference between smooth function and a bolt that won’t close.
Most sizing dies are reamed one-piece, one-shot like a rifle chamber; however, that’s not always the method. Some are done in two or more steps, using two or more cutting tools. Clearly, consistency and correctness favors the one-piece reamer. Assuming that the reamer is correct and correctly used. I have encountered one die that just wasn’t concentric, body chamber to neck area. I figured that one out by sizing without the expander and checking runout, and also by finding that I could shift off-center axis by rotating the (marked) case and running through again. Normally, sizing a case without the expander in place results in a case that runs flat-line on a concentricity fixture. Reason is primarily because any inconsistency in the case neck walls get “pushed” to the inside case neck. But if there’s wobble in a case that’s been sized sans expander, then, son, you got a die problem.
A bent or bowed expander stem will, not can, result in an expander that’s going to cock the case neck one direction. I watch for that when I polish the expander button. As described here before, that process involves chucking the stem (lightly) in an electric drill and spinning the ball against some wet emery to give the ball a shine. If it’s wobbling during this operation, that’s a problem.
Seating die issues, in my experience, usually revolve around plain old straightness of the seating stem, and, once, the concentricity of the reamed case body area. If you have a seating die that increases runout compared to what a concentricity fixture showed on the sized case neck, it needs looked into. Additionally, always (always) check to make sure the seating plug (the area that fits over the bullet to push it into the case neck) is deep enough the the bullet tip does not make contact with the inside of the plug. That’s a sure way to get a bullet tipped off kilter.
Now. Most importantly: What to do if you suspect a tooling problem? Short answer is: SEND IT BACK. Don’t accept it. I know of no maker who won’t profusely apologize and promptly return a new one. The fixes I mentioned are for those who prefer to solve such issues, and also for those who have the means to effect repairs. The point to this article mostly is to be aware that problems can and do exist, and don’t accept them, whichever direction you seek for the solution.
No matter how precisely a die maker produced the parts, there is and will be some gap in threaded pieces. This can disguise itself as a “die” problem, but it’s really not. It’s a set-up problem. I did an article a good while back here on a few ideas on improving tool/case alignment via some set-up tricks, and maybe that should be the next topic under the Reloaders Corner banner.
The information in this article is from Glen’s newest book, Top-Grade Ammo, available HEREat Midsouth. Also check HEREfor more information about this and other publications from Zediker Publishing.
In this final installment you’ll learn how to take bullet jump completely out of the equation, but it’s not just that simple… Here’s how to get the results you’re after. Keep reading…
There’s one more concept to consider to fully finish the topic of bullet seating depth, and it’s literally on the other end of the equation from discussions on bullet jump.
Last two articles were all about a combination of the evils of jumping bullets and also some ideas on reducing the ill effects, and hopefully to the point of zero measurable group size differences. I also mentioned that there are some bullets that just don’t tolerate jumping.
For many (many many) years it’s been generally held that starting a bullet touching the lands is the easy ticket to better accuracy. That’s hard to disprove. It’s a tactic very commonly used by Benchrest and Long Range Rifle competitors, and savvy long-shot hunters. Now we’re talking about zero jump. Myself and many others have referred to this bullet seating tactic as “dead-length” seating. To be clear: it’s the cartridge overall length that has the bullet nosecone actually sitting flush against the lands (touching on whichever point along the nose that coincides with land diameter). Some literally take that a step farther and increase contact force such that the bullet is sticking into the lands one or more (sometimes several more) thousandths, actually being engraved by the lands prior to launch.
There are two ways to attain or approach dead-length. One is through careful measurement using something like a Hornady LNL Overall Length Gage. That tool should be paired with a bullet-length comparator, and Hornady has one of those too, as do others.
Measure enough bullets using a bullet-length comparator and you will find length differences in a box of most any brand. A comparator, as has been shown before in my articles (because it’s a very valuable tool to increase handloading precision), provides a more accurate means to measure bullet length. It’s a simple tool: the bullet nosecone fits into the opening on the gage, stopping at a point (determined by tool dimension) along the nosecone. Not all such gages coincide with land diameters because both comparators and land diameters vary from maker to maker. They are all “close” but perfect coincidence doesn’t really matter because a comparator will allow a reading at the same point of diameter regardless. Measuring from the base of a bullet to the bullet tip is inaccurate, and not nearly “good enough” to provide a precise enough measurement to venture into lands-on seating depth experiments. The reason measuring from base to tip isn’t good enough is because, especially in hollowpoint match-style bullets, there are relatively huge variations in the consistencies of the tips. I’ve measured easy 0.020 differences in a box of 100. Can’t make bank on that.
Using the combination of the gage that shows overall cartridge length that has the bullet touching the lands and the comparator to precisely record this length, it can then be reproduced via seating die adjustment.
Here’s a tool set shown many times in my books and articles this pair or something similar is necessary to negotiate this step in handloading. Check it out HERE and HERE at Midsouth.
If using this method, maintain whatever usual neck sizing dimensions are for your routine loads. There’s no need or benefit from lessening the case neck “tension” (which is the amount, in thousandths of inches, of the difference between resized case neck outside diameter and the resulting diameter after a bullet is seated). If that’s, say, 0.003 then keep it at 0.003.
There’s another, maybe better, method to follow if (and only if) you have a bolt-gun that’s to be fed one round at a time. By that I mean the rounds are not feeding up from a magazine but are being manually inserted into the chamber. That method is to reduce the case neck tension or grip to a level that the bullet is free enough to move within the case neck such that it seats itself when the round is chambered and the bullet makes contact with the lands. That’s awfully light in-neck resistance. It can’t be so light that the bullet falls into the case neck, but light enough that it can be scooted more deeply with little pressure. For a number it’s 0.001, minus, and half of that is workable if the case necks have been outside turned (so they are dead consistent in wall thicknesses and therefore will reliably “take” that little tension, meaning respond consistently to the sizing operation). Need a bushing-style sizing die to get that sort of control over the neck sizing dimension.
This method is often called “soft seating.” It’s, as said, very popular with competitive precision shooters. The bullet, keep in mind, isn’t just touching the lands, it’s actually engaging the lands to whichever degree or distance that resulted from overcoming the resistance from the case neck. If you feel anything more than slight resistance in chambering a round, that’s too much resistance. Chances are that any soft-seated bullet will stick in the barrel so extracting a loaded round will likely result in a big mess (elevate the barrel a little to keep the propellant from dumping into the action). Pushing the lodged bullet back out and looking at it carefully gives a good idea of how much resistance it’s overcoming. If the engraved area is much over 1/16-inch, increase the neck sizing bushing diameter to likewise loosen up the case neck. The amount of engraving has a whopping lot to do with the bullet jacket material (you’ll see more with a J4 than with a Sierra).
If you follow this method, then finish the die-seated bullets “out” 0.005-0.010 inches.
The reason this method can give the overall best results is because it’s accounting for teeny differences in bullet ogives and it also is adjusting itself for throat erosion. As gone on about in the last couple of articles, a barrel throat is lengthening with each round that passes through. What was touching the lands, or jumping 0.015, even one hundred rounds ago is no longer valid, and it’s totally corrupt five or six hundred rounds later. It’s no longer a precise setting, meaning a precise seating depth, and it has to be checked and reset as the barrel ages.
Again, this is not a casual experiment. The level of control and precision necessary to make it work safely and as expected is a step or three beyond what most reloaders are tooled up to deliver.
Will lands-on seating work for a semi-auto? Yes. But only with adequate bullet grip to retain the bullet firmly in the case neck, and that means the same tension that would be used with any other cartridge architecture, and that means a minimum of 0.003 inches difference between sized and seated outside case neck diameters. I do it often with my across-the-course High Power Rifle race guns. Clearly the “soft-seating” tactic is in no way wisely feasible in a semi-auto.
WARNING! MOVING A BULLET OUT SO IT TOUCHES THE LANDS WILL (not can) INCREASE LOAD PRESSURE! Even going from 0.001 off to flush on will spike pressure. When the bullet is in full contact it’s acting like a plug. I strongly suggest backing off one full grain (1.0 grain) before firing a bullet touching the lands. Then follow my “rule”: work up 0.2-grains at a time but come off 0.5-grains at a time! If there’s ever any (any) pressure symptom noted, don’t just back of a tenth or two, that’s not enough, not considering all the other little variations and variables that combine to influence the behavior of the next several rounds you’ll fire.
THREE REASONS DEAD-LENGTH SEATING WORKS ONE: Accounts for and overcomes any minor variations in bullet dimensions. TWO: Minimizes bullet jacket disruption on entry. THREE: Virtually eliminates misalignment between bullet and bore.
SIDE NOTE If you’re one who, as many readers have suggested to me, has found that seating a bullet to touch the lands is the only way they get good groups, consider the above three reasons this seating method works and then interpret. If, and this is more common than we’d like to see, you’ve got a factory bolt-action rifle the chamber is likely to be overly generous in size or a tad amount non-concentric, or both. The case wall consistency and also sizing and seating tooling, or all three, might likewise be sub-par. In other words: lands-on seating is overcoming a few rifle issues, not, in itself, proving it’s the one-way ticket to great groups. Mostly, getting the bullet into the lands essentially straightens out alignment of the whole cartridge sitting in that (maybe) big chamber.
The information in this article is from Glen’s newest book, Top-Grade Ammo, available HEREat Midsouth. Also check HEREfor more information about this and other publications from Zediker Publishing.
Tips that help take bullet jump out of the accuracy equation. Find out how!
Last time I shared some insight about bullet “jump,” and specifically with respect to the viability of setting up a “zero-jump” chamber/ammo combination.
To hit the highlights: Jump is the gap the bullet must traverse when it leaves the case neck to engage the lands or rifling. Generally, best (and better) accuracy comes with this gap is reduced to a minimum amount, or at the least reduced. Better is better.
To go farther into this topic, it’s worthwhile to move the bullet around, seating it more or less deeply (nearer or farther from the lands at rest) to maximize accuracy. Clearly, there’s a limit on cartridge overall length if the rounds have to fit into a magazine box so they can feed right. In NRA High Power Rifle competition, the AR15 pilots are specifically not allowed to have the rounds feed from the magazine in semi-auto mode; each round must be loaded into the chamber one at a time for the “slow-fire” segments, which includes the 600-yard event. That means competitive High Power shooters using AR-platform rifles are free to move the extra-long 80+ grain .224-caliber bullets out to near or on the lands when chambered. That doesn’t really matter but it explains the popular “Wylde” chamber we tend to use. It’s got a long enough throat to free more case volume and also provide a bigger “expansion chamber” for burning propellant gases, but it’s not as long as a NATO-spec so should perform better with bullets that do have to be loaded deeply in enough to fit the magazine box. Something like a Sierra 80gr or 82gr Berger won’t usually shoot worth a flip loaded to mag-length. That bullet, and others similar, are simply too dang long for a .223 Remington case. A huge amount of the bullet swallows up the case interior.
The best defense against ever worrying over jump, meaning whether you’re getting good accuracy regardless of the amount of bullet jump (well, at least within reason…) is bullet choice. Specifically, a tangent-profile bullet with a conservative ogive. Recollecting from some materials I did a while back, a “secant” profile is a sharper taper-in from bullet body to bullet tip; a tangent is a smoother transition. Secants, more or less, have a “shoulder” indicating a more abrupt taper rather than a smooth arc. For examples: true VLD (very low drag) and the Hornady A-Max are secant.
Bullets with relatively shorter nosecones and relatively longer bearing areas (length of the bullet that’s in contact with the rifling) are likewise more tolerant of jump.
There’s been a trend for many years now toward creating bullets with higher ballistic coefficients. Worthwhile pursuit! Only issue is that when a bullet design features better aerodynamics, the features of that are, yep, longer nosecones with shallower angles. The ogive (what I’ve been more descriptively calling the nosecone because it’s easier to picture) usually is expressed in calibers. Technically it’s “calibers of ogive,” and that’s the ogive radius divided by the caliber. To me it’s easier to picture looking at the “other side” of the equation: the arc that scribes the profile in multiples of the bullet’s caliber. So, a 7- to 8-caliber ogive is a tighter circle (more rounded profile) than a 12- or 15-caliber ogive. Most of the “high-BC” profiles use a 15, some more. In other words, they’re stilettos.
I’m kind of breaking this down farther and faster than exercising good technical care in covering this topic should warrant, but: comparing both same-weight and same-caliber bullets, the longer it is the more sensitive it’s going to be to jump.
I have shot way too many high-X-count 300-yard cleans with bullets jumping 0.030+ inches to say that it’s not possible to have good accuracy unless jump is minimal. I admit that’s only a 1 moa group. I’m also using what some makers call a “length-tolerant” bullet, and specifically that’s a 77gr Sierra Matchking, and the same goes for a Nosler 77 or Hornady 75 HPBT (not A-Max). It’s the bullet form, not just its weight, that has the strongest influence on all this.
So, do you have to abandon better ballistics to attain better accuracy? Maybe. At least to a point. With the smaller calibers, which don’t have other advantages larger calibers have simply by virtue of weight and sectional density, there tends to be an effectively greater discrepancy between the lighter and heavier (again, it’s really shorter and longer) bullet ballistic performances.
A rifle with a generous-length magazine box provides greater jump-reduction via loaded round architecture. If there’s enough room, a bullet can be scooted out to the limit of the space within the box.
As always, well at least usually, there are tools! Get them and use them. A gage “set” from Hornady is well advised. There are others similar. I’ve been using their LNL Overall Length Gage and Bullet Comparator for many years and receive needed results. The first tool indicates the seating depth that touches the lands, and the second provides more reliable and accurate means to measure and record it.
The leade, which, again, is the transition to the lands and determined by the chambering reamer (or throating reamer if custom-done) does influence tolerance for jump. The shallower the angle the better, but, that’s a two-edged issue. Take a commonly-used 3-degree leade and make it a more preferable 1.5-degree leade and that takes way on more than double the distance (length of cut) to attain. Again, when there’s a magazine getting in the way of bullet seating depth flexibility, a shallower leade eases transition into the barrel bore for a jumping bullet, but also increases jump. There are some cartridges, like David Tubb’s 6XC, that were designed specifically to “perfect” all these relationships: magazine-mandated cartridge overall length, bullet choice, and leade in, and it’s one reason it owns the records it does. Otherwise, it’s often a compromise… But don’t compromise accuracy for anything. A smaller group is, in the long run, the best defense against both wind and distance when it comes to hitting a target. Reliable feedback equals correct adjustments.
The distance a bullet travels to enter the lands is a topic of much concern to the precision shooter. This series takes a look at why it matters, and also when it doesn’t…
Bullet jump: the open space a bullet must span until its first point of sufficient diameter engages the barrel lands.
Last week I had a long phone conversation with a fellow who had been bitten by two bugs, two somewhat conflicting bugs (at least seemingly so on the onset). The one was a regrouping equipment project for USPSA-style practical rifle competition, and the other was for a desire to maximize accuracy, which is to minimize group size. This fellow had been involved in competition long enough to decide to stay with it, and was re-upping his AR15 upper with a new custom barrel. He wanted to have the best accuracy he could buy, and that’s a worthwhile pursuit as long as there’s a budget that supports it.
The subject of bullet jump became the dominant topic.
Yep, he had read my books and a few others and developed the impression that minimizing bullet jump was one crucial component to maximizing accuracy. That’s fair enough. I’ve gone on about it, as have others. Adjusting bullet seating depth can make a big, big difference in shot impact proximities. However! The reason bullet jump matters — usually — is largely, almost exclusively, because of some bullet profiles being more finicky than others. Namely the longer and spikier “very-low-drag” type bullet profiles.
The first point of “major diameter” on a bullet is what coincides with the land diameter in the barrel. If that’s a .22 caliber with 0.219 diameter lands, then the first point along the nosecone of a bullet that’s 0.219 is the distance. Gages that measure this distance (Hornady LNL for instance) aren’t necessarily going to provide perfect coincidence with land diameter, but still provide an accurate bullet seating depth that touches the lands.
If you find the cartridge overall length, which really means bullet seating depth, that touches the lands (coincides with land diameter) then subtract that from what you then measure when the bullet is seated deeply enough to fit into a magazine box, that right there is the amount of jump.
Dealing with an AR15, or any other magazine-fed rifle, assuming we are wanting the rounds to feed from the magazine, is that there’s a finite cartridge overall length that will fit into the magazine. So. We’re almost always going to be dealing with some amount of jump, unless one or two things can be manipulated to reduce or eliminate it.
The one is that the influence of rifle chamber specs with respect to either more or less jump is pretty much exclusively in the leade or throat. That’s the space that defines the transition from end of the chamber case neck area to entry into the lands. The closer the lands are to the chamber neck area the shorter the jump will be with any bullet. That is the leading difference between a SAAMI-spec .223 Remington chamber and a 5.56 NATO chamber. The NATO has a much longer throat. I’ve written on that one a few times…
A shorter throat has goods and bads. The main good is that, indeed, any and all bullets are going to be closer to the lands in a round loaded to magazine-length.
But the “two” in the things that influence jump is bullet selection. It is possible to find a combination that will easily have the bullet sitting right on or very near the lands at the get-go. That’s going to be a short, and light, tangent ogive bullet within a SAAMI-spec .223 Remington chamber, or (and this is what I have done) a barrel chamber finished using a throating reamer to get even closer. In general: the nearer the first point of major bullet diameter (remember, that’s the land diameter) is to the bullet tip, the shorter the jump will be, and that’s because this point is “higher.”
Throat erosion is going to lengthen the throat. Can’t stop that. The cartridge structure that was jumping, say, 0.005 on a new barrel is jumping more than that after literally every round fired through it. After some hundreds of rounds it’s jumping a few multiples of 0.005. (How much or how many is not possible to forecast because way too many factors influence the amount and rate of throat erosion. Just have to keep checking with the gage I suggest you purchase.) This is the reason I specify a custom dimension to get reduced jump: with the right hands using a throating reamer it’s easily possible to maintain land contact at magazine length seating even after a lot of rounds have gone through. Bullets will begin being seated more deeply and then get nudged out as the throat erodes.
So, where the conversation ended was this: If (and only if) someone is willing to take the time and make the effort to carefully establish and then control a reduced or eliminated amount of magazine-loaded jump then, yes, it’s a fine idea! It’s also an idea that likely will result in the best accuracy. I’ve done it in one of my AR15 match rifles, and it’s the best shooting I’ve ever owned. The hitch is that the rifle becomes what I call a “one-trick pony.” It’s not always going to accept bullets and loaded round architectures that stray from the carefully calculated dimensions originally set down. It’s also not likely going to perform safely with every factory-loaded round out there, and you can forget (totally forget) ever firing a NATO-spec round.
There’s a whopping lot more to this whole topic, and we’ll look at the other end of the spectrum next time.
The reason that reduced amounts of bullet jump increase accuracy, in a perhaps overly simple but entirely correct way to understand it, is because there’s simply less potential for disruptive entry into and lands and then through the bore. There’s less misalignment opportunity, less jacket integrity disruption opportunity. There is a lot more that can be discussed in finer points, of course…
Determining and setting the correct case neck diameter is a critical, crucial step in the handloading process: Here’s all you need to know!
Here’s another I get (too many) questions about, and when I say “too many” that’s not at all a complaint, just a concern… This next hopefully will eliminate any and all confusions about this important step, and decision, in the reloading process.
Basics: A cartridge case neck expands in firing to release the bullet. If the load delivers adequate pressure, it can expand to the full diameter allowed by that portion of the rifle chamber. That diameter depends on the reamer used. After expansion and contraction, the case neck will, no doubt, be a bigger diameter than what it was before being fired.
Back to it: To get a handle on this important dimension, the first step is tools. As always. A caliper that reads to 0.001 inches will suffice.
You need to find three outside diameter numbers: fired case neck diameter, sized case neck diameter, loaded case neck diameter. If you know the loaded case neck diameter then it’s likewise easy to find out the case wall thickness, or at least an average on it if the necks aren’t perfectly uniform (and they won’t likely be unless they’ve been full-on outside case neck turned).
A fired case neck has to be sized back down to a dimension that will retain a bullet from unwanted movement (slippage) in the reloaded round. Case neck “tension” isn’t really an accurate term, in my mind, so I prefer to talk about “constriction.” The reason is that making a case neck diameter smaller and smaller does not, after a point, add any additional grip to the bullet. Once it’s gotten beyond maybe 0.005 inches, it’s just increasing the resistance to bullet seating not increasing the amount of tension or retention of the case neck against the bullet. The bullet is resizing the case neck, and probably getting its jacket damaged in the process. If more grip is needed, that’s where crimping comes in…and that’s (literally) another story.
IMPORTANT Always, always, account for the “spring-back.” That is in the nature of the alloy used to make cases. If brass is sized to a smaller diameter it will spring back plus 0.001 inches bigger than the tool used; if it’s expanded to a bigger diameter, it will spring back (contract) to 0.001 inches smaller than the tool used. This is always true! The exception is that as brass hardens with age, it can spring back a little more.
How much constriction should there be? For a semi-auto, 0.003 is adequate; I recommend 0.004. For a bolt-action, I use and recommend 0.002, and 0.001 usually is adequate unless the rifle is a hard-kicker. See, the main (main) influence of more resistance in bullet seating is to, as mentioned, set up enough gripping tension to prevent unwanted bullet movement. Unwanted movement can come from two main sources: contact and inertia. Contact is if and when the bullet tip meets any resistance in feeding, and gets pushed back. Intertia comes from the operation and cycling of the firearm. If there’s enough force generated via recoil, the bullets in rounds remaining in a magazine can move from flowing forces. However! That also works literally in the other way: in a semi-auto the inertial force transmitted through a round being chambered can set the bullet out: the case stops but the bullet keeps moving. I’ve seen (measured) that happen with AR15s and (even more) AR-10/SR-25s especially when loading the first round in. Put in a loaded magazine, trip the bolt stop, and, wham, all that mass moves forward and slams to a stop. Retract the bolt and out comes a case with no bullet… Or, more usually, out comes a case with the bullet seated out farther (longer overall length). Never, ever, set a constriction level on the lighter side for either of these guns.
Most seem to hold a belief that the lower the case neck constriction the better the accuracy. Can’t prove that by me or mine. If there’s too much constriction, as mentioned, the bullet jacket can be damaged and possibly the bullet slightly resized (depending on its material constitution) and those could cause accuracy hiccups. If it’s a semi-auto and constriction is inadequate, the likewise aforementioned bullet movement forward, which is very unlikely to be consistent, can create accuracy issues, no doubt. My own load tests have shown me that velocities get more consistent at 0.003-0.004 as compared to 0.001-0.002.
Benchrest competitors use virtually zero constriction, but as with each and every thing “they” do, it works only because it’s only possible via the extremely precise machining work done both in rifle chambering and case preparation. It is not, decidedly not, something anyone else can or should attempt even in an off-the-shelf single-shot. As always: I focus here, and in my books, on “the rest of us” when it comes to reloading tool setup and tactics. Folks who have normal rifles and use them in normal ways. And folks who don’t want to have problems.
So, find out what you have right now by determining the three influential diameters talked about at the start of this article. Most factory standard full-length sizing die sets will produce between 0.002 and 0.003 constriction. Getting more is easy: chuck up the expander/decapper stem in an electric drill (I use oiled emery cloth wrapped around a stone), and carefully reduce the expander body diameter by the needed amount, or contact the manufacturer to see about getting an undersized part. I’ve done that.
If you want less constriction than you’re currently getting, about the only way to do that one is hit up a local machinist and get the neck area in the die opened by the desired amount (considering always the 0.001 spring-back). Or get a bushing-style die…
The bushing-style design has removable bushings available in specific diameters. Pick the one you want to suit the brass you use. If you run an inside case neck expanding appliance along with a bushing die, usually a sizing-die-mounted “expander ball” or sizing button, make sure you’re getting at least 0.002 expansion from that device. Example: the (outside) sized case neck diameter should be sufficiently reduced to provide an inside sized case neck diameter at least 0.002 smaller than the diameter of the inside sizing appliance. That’s done as a matter of consistency and correctness that will account for small differences in case neck wall thicknesses. And when you change brass lots and certainly brands, measure again and do the math again! Thicker or thinner case neck walls make a big difference in the size bushing needed.
The M14/M1A can be a cantankerous beast to reload for, so follow these suggestions to tame it down. Keep reading…
The “5 steps to success” are at the end of this article… First, read about why they will matter as much as they do!
A couple times back I decided that the best topic to write about might be the most current, and I defined that by the most recent questions I fielded on a topic. As the assumption goes: they can’t be the only ones with that question… So, over this weekend I had a series of questions from different people all on the topic of reloading for the M1A, the civilian version of the military M14.
Now. Since the M14 was the issue rifle of choice for a good number of years, and without a doubt the (previously at least) favored platform for the various-branch military shooting team efforts, it went through some serious modifications to best suit it to that very narrow-use objective: High Power Rifle competition. Although the M14 hadn’t been routinely issued to most troops for decades, it was still going strong in this venue. That changed in the mid-90s when Rules changes boosted the AR15 platform to prominence, and soon after, dominance.
Match conditioning an M14 involved modifications to virtually every system component, and resulted in a fine shooting rifle. Very fine. Amazingly fine. The one mod that prodded the impetus to write all this next was the barrel chambering specification changes. A while back I went on about what 7.62 NATO is compared to its fraternal twin .308 Winchester.
Match-spec M14 chambers are decidedly NOT NATO! They’re .308 Winchester, pretty much. I say “pretty much” because they’re on the minimum side, dimensionally, compared to SAAMI commercial guidelines for .308 Win. Lemmeesplain: the true “match” M14 chamber is short, in throat and in headspace. The reason is ammunition bound. I’ll explain that too: Lake City Match ammo was and is a universal competition cartridge. Military teams compete in, well, military team competitions. Some are open to civilians, some are not. All, however, used issued ammo across the board. You were given your boxes of Lake City Match, or Special Ball, or one of a couple other same-spec variants, prior to the show and that’s what you used for the event. Everyone used the same ammo. Civilian or Service. There were exceptions, like long-range specialty events, but what was said held true the vast majority of the time. That meant that everyone wanted the same well-proven chamber, civilians too.
Given this, that’s why a “match” M1A chamber is different than a SAAMI. It was built to maximize Lake City Match accuracy. That’s a short round. The headspace is a few thousandths under what’s common on a chamber based around commercial .308 brass. 1.630-inch cartridge headspace height is regarded as minimum for commercial.
So sizing a case to fit a match M1A, especially if it’s a hard-skinned mil-spec case, takes some crunch. To compound difficulty, M1As and M14s unlock very (very) quickly during firing. The bolt is trying to unlock when the case is still expanded against the chamber walls. The little bit of space this creates results in a “false” headspace gage reading on the spent case. It’s going to measure a little longer than the chamber is actually cut. That can lead someone to do the usual math (comparing new case and spent case headspace reads) and end up with a “size-to” figure that’s too tall, that has the shoulder too high. For instance, let’s say the spent case measured 1.634 and the new case measured 1.627, indicating 0.006 expansion or growth. Given the usual advice (from me at least) to reduce fired case shoulder height by 0.004 (semi-autos) for safe and reliable reuse would net a size-to dimension of 1.630. But. There can easily be a “missed” 0.002-0.003 inches resultant from the additional expansion explained earlier. My advice for a match-chambered M1A is to reduce the fired case all the way back down to the new case dimension. That might sound like a lot, and it might sound excessive, and it might be — but, it’s the proven way to keep this gun running surely and safely. That, however, is not always an easy chore. Some mil-spec brass is reluctant to cooperate. And, by the way, don’t kid yourself about reducing case life. This gun eats brass; I put just three loads through a case before canning it.
Two helps: one is to use petroleum-based case lube, like Forster Case Lube or Redding/Imperial Sizing Wax. And size each case twice! That’s right: run each one fully into the die twice. Double-sizing sure seems to result in more correct and more consistent after-sizing headspace readings.
A “small-base” sizing die (reduced case head diameter) is not necessary to refit match brass into a match chamber. It might help using brass that was first-fired in a chamber with more generous diameter, but sized diameter isn’t really the “small” part of the M1A match chamber. Again, the small part is the headspace.
So that’s the source the problem reloading for this rifle. And, again, “this rifle” is an M1A with a true mil-match armorer’s spec chamber. We best make sure that our sized cases are going to fit the chamber, plus a couple thousandths clearance for function and safety. And safety mostly. M1As are notorious for “slam-fires” which happen when the free-floating firing pin taps the primer on a chambering round delivering sufficient intrusion to detonate. Impressive explosions result. If the case shoulder is stopping against the chamber before the bolt can lock over, that can be all the pin needs to maximize the effect of its inertia.
Speaking of, there are three sources and fortunately the same number of cures for slam-fires. One, first, is the correct sizing on setting back the case shoulder so the shoulder doesn’t stop against its receptacle in the chamber. Next is making sure there are no “high” primers; each primer should be seated at least 0.005 inches under flush with the case head. Next, and very important: primer composition, which equates to primer brand. Do not use a “sensitive” primer, one with a thinner, softer skin. Although they are great performers, Federal 205 are too sensitive for this rifle. Better are WW, CCI 200.
I don’t like this chamber… I also used one because I competed in events with issued ammo. I don’t recommend a “true” M14 chamber because that’s a NATO. Plain old standard .308 Win. specs work better and allow more flexibility in ammo and component selection. Even though the true mil-spec match chambers are not common, the reason I’ve written as much as I have on this topic over the years is because a mistake can be disastrous. One of the folks who wrote me one question shared a story about a friend who blew up his match M1A firing improper commercially-loaded ammo through it. Whoa.
A CASE FOR THE M1A This gun needs a stout case. They won’t last long no matter what but they might not last at all if they’re too soft. I’ve broken some new commercial cases on one firing. Thicker/thinner isn’t the issue: it’s the hardness of the alloy. Harder material better resists reaction to the additional stress of premature system operation. New-condition mil-spec cases are great, if you can get them. Next best is Lake City Match that was fired in a match-chambered rifle. Stay completely away from anything, and everything, fired through a NATO-spec chamber. It’s nigh on not possible to size them enough to suit. For me, WW is the only commercial case I will run through my M1A. They’re thin, but pretty hard.
I did a whole chapter solely on reloading for the M14/M1A for my book Handloading for Competition that didn’t get printed into it for various reasons. However! I have the entire chapter available as a PDF download on my website. Get it HERE
Don’t overlook details when setting up shop. Here are a few ideas on dealing with a few tools and tasks to get set up to reload.
Time after time, point after point, I address the use of specific tools used in the process of loading ammunition. There are a few tools that never get near a cartridge case or bullet, though, that matter much to contentment. These are the “set-up” tools and appliances that when needed are indispensable. And, as with the loading tools themselves, making the better choices pays off. I joke with myself sometimes that I spend about as much time at auto parts and hardware stores as I do reloading industry outlets…
Get real wrenches for all the dies and tools you own. It’s worth the investment to buy a quality combo wrench at an auto-parts store rather than buggering up all your fasteners with a set of slip-lock pliers. But. You need those too. Everyone needs a slip-joint pliers, like Channellock-brand, but avoid using it whenever possible. Again, correctly-sized quality wrenches won’t muck up your die parts.
A good quality set of allen wrenches, or hex-heads, likewise is a relative joy to use next to the el-cheapo versions that come with the tools. Get the ball-end kind for even easier use.
Press and Tool Mounting
Make an investment in at least “good” grade tools for drilling holes and measuring where to drill them, and then for installing the fasteners. It really makes a difference to have proper size drill bits and drivers.
The press is the base for the dies. It’s important. Of course it is. Mounting is key. I suggest a workbench that’s mounted to a wall, along with its legs fixed down to the floor. It’s the press upstroke, not the downstroke, that taxes the stability or solidness of the workbench.
If you’re building a workbench, consider carefully the overhang and bench-top underside construction, or at least dimensions. What you don’t want, and what I have had so I know, is a combination of press hole mounts that conflict with workbench construction. Like when there is a structural crosspiece right underneath where a hole has to bore through. That’s a mess to deal with, or it can be. Then you have to drill a hole big enough to give a window to install a washer and a nut, and then that nut won’t want to stay tight. Check first before you settle on your plans. 6 inches of overhang (free underside) mounts anything I’ve yet used.
Do a template for press mounting. That’s easy by doing the “rub trick” with a soft pencil on a piece of paper taped to the press underside; some manufacturers provide templates, and that’s a nice touch. Otherwise, use a centering tool to mark the holes, used through the mounting holes on the press. Even being a little bit off hurts wonders. And drill straight! Get a drill with a level-bubble. The thicker the bench-top, the more mess a small angle error makes.
A cool trick for drilling holes in laminate or wood is to put masking tape over the marks for the drill bit start marks before boring. This keeps the material from splintering. Never (ever) use the press holes themselves as a guide for the drill bit.
I strongly suggest backing up the underside bench nuts with washers. Otherwise there will be compression of the nut into the bench material, and ultimately result in loosening. This is actually very important… Use a fender (flat) washer next to the wood, and a star (locking) washer between the nut and the fender washer (stars face the nut underside), or use nuts with “nylock” inserts.
After mounting the press securely, keep it secure. Check all the fasteners especially after the first use. And, as just recommended, here’s where washers and locking fasteners help. As said, the washers help avoid the compression into a wooden benchtop that can otherwise ultimately lead to a lifetime of snugging down the bolts — they’re not tightening, they’re just pushing in deeper… The locking fasteners are resistant to stress-induced movement.
I have increasingly become a fan of using threaded retainers in place of nuts to screw the bolts to. This is a great means to secure things like case trimmers, powder meters, or anything else that might need to come on and then off the workbench area. Threaded inserts, such as t-nuts, remain in place on the bench top underside and the bolts are just run down into them. That makes it simple to mount and dismount with allenhead screws. Less benchtop clutter also.
Shop rags work better than anything, and that’s why they’re used in shops. Sometimes the obvious is true. Get them at an auto parts store.
Invest in some good rust preventative and then use it. A lot of the tools we use don’t have any or adequate protective finishes on them, so give them a wipe-down after use. Local climate has a whopping lot to do with the need and frequency for this. Plus, there’s always going to be unforeseen times you’ll need to free a stuck fastener. Kroil-brand penetrating oil is the best I’ve used. Tip: Always grease contact points between steel and aluminum. If you don’t it will “freeze.”
Light is an asset, and, especially as eyes get older (dang I hate to say that, so let’s say the more and more someone needs bifocals and won’t get them) some magnification is a help too at times. It’s easy to find one of the clamp-on arm-style magnifying lights at most office supply stores, and even easier to locate a pair of reading glasses.
Some confuse these operations. Don’t! Here’s what each is, and isn’t…
I get a lot of questions. I always answer each one, and in doing so that experience reminds me of the wide span of topic knowledge needed to be a successful, and safe, handloader. I make an effort not to assume any level or depth of anyone’s understanding of any topic I might address. At the risk of “offending” all the experts out there by wasting their time with fundamental starts to technical pieces, I’d dang sho rather bore them than shortchange a newcomer out of elemental information.
I told folks in my last book that “grains” refers to a propellant weight, not a kernel-count. Right. But I’ve fielded that question more than once. That’s not, in my mind, a “stupid” question. Truth: The only stupid question is one that’s not asked, when there’s a need to know.
So, that was leading into this: Here’s a question I got just yesterday that sourced via someone who wasn’t even a little bit uneducated in the need for finer points of case prep. This fellow was confused about the relationship between inside case neck reaming and outside case neck turning. Here’s a longer version of the answer I returned to him —
First, there is no relationship between inside neck reaming and outside neck turning, and by that I mean they are not a combined process. As a matter of fact, these should not be combined!
They can be confused because they both ultimately accomplish the same thing, the same basic thing: each process removes material from a cartridge case neck cylinder, and that makes the case neck wall thinner. These two ops, however, are done for two different reasons.
An inside case neck reamer is intended to relieve excess material from case necks that have thickened excessively through use and reuse. Brass flows, and it flows forward.
Important! Most “standard” case neck reamers are intended to be used on fired, but not yet resized, cases! In other words: Use the reamer on the fired cases as-are. Do not use one on a case that’s had its neck resized because that will cut away way too much brass.
Another application where inside reaming is frequently recommended is in forming operations that require a reduction in case neck diameter. When a case is “necked down,” which means run through a sizing op that creates a .243 caliber from a previously .308 caliber, for instance, the neck walls thicken. An appropriately-sized reamer makes the shortest work of this tedious but necessary job. Most forming die packages either include or make mention of the specific-size reamer to use.
Outside case neck turning is done to improve the consistency of case neck wall thickness around the cylinder. It’s a step taken to improve accuracy. Outside case neck turning should be done only on brand new (unfired) brass. It’s more precisely effective and easier because that’s when the alloy is at its softest.
There are specific, custom combinations that require a smaller than standard case neck outside diameter. The “tight-necked” rifle, which is just about exclusively encountered in Benchrest competition, has to have its brass modified to chamber in the rifle. The neck area of the rifle chamber is cut extra-small to provide a means to attain a “perfect” fit and minimal case neck expansion. If you’re into this, then you already knew that…
So, the primary role and use of an inside neck reamer is as a safety precaution; its secondary use is as a prep step in case forming. The primary role and use of an outside neck turner is to improve the consistency, quality, of a case neck cylinder. The idea is that more consistent wall thickness leads to a more centered case neck. And it does. Reaming does zero to improve consistency. Reaming just makes a bigger hole of the hole that’s already there; it doesn’t relocate its center.
Combining these ops might create a safety issue because the necks might get too thin, and that could mean there wouldn’t be enough grip on the bullet. Point is, ultimately, that reaming and turning are not equivalent even though they might seem to be doing the same thing. One is not a substitute for the other. It certainly would be possible to remove metal from the outside of the neck cylinder to overcome the effects of thickened necks, if (and only if) the neck is sized again using the usual die apparatus. When that’s the goal, though, a reamer is lower effort, faster, and less expensive to buy into.
Very important! Always (always) culminate either operation by running the cases a trip through the sizing die you normally use.
Understanding the relationship between bullets and barrel twist helps prevent mistakes. Here’s what you need to know…
Why am I devoting this space this time to such a topic? Well, because it’s commonly asked about, and, no doubt, because it influences some of the decisions and options faced in choosing the best-performing load for our needs. Making a mistake in choosing twist can limit both the selection and performance in the range of usable bullet weights and styles.
First, barrel twist rate is a component in the architecture of the barrel lands and grooves. The lands and grooves form a spiral, a twist, that imparts spin to a bullet, and the rate of twist is expressed in terms of how far in inches a bullet travels to make one full rotation. “1-10” (one-in-ten) for example means “one full rotation for each ten inches of travel.”
Bullet length, not weight, determines how much rotation is necessary for stability. Twist rate suggestions, though, are most usually given with respect to bullet weight, but that’s more of a generality for convenience’s sake, I think. The reason is that with the introduction of higher-ballistic-coefficient bullet designs, which are longer than conventional forms, it is easily possible to have two same-weight bullets that won’t both stabilize from the same twist rate.
The M-16/AR15 barrel changes give a good example. Short history of mil-spec twist rates: Originally it was a 1-12, which was pretty standard for .224-caliber varminting-type rounds, like .222 Remington, which were near-universally running bullet weights either 52- or 55-grain. That worked with the 55-grain FMJ ammo issued then. Later came the SS109 63-grain round, with a bullet that was a bit much for a 1-12. The military solution was total overkill: 1-7. That’s a very fast twist.
Commercially, the 1-9 twist became the standard for .223 Remington for years. It’s still popular, but is being replaced, as far as I can tell, by the 1-8. An increasingly wider selection of barrels are done up in this twist rate. I approve.
I’d always rather have a twist too fast than not fast enough. For a .223 Rem. 1-9 is not fast enough for anything longer than a routine 68-70-grain “magazine bullet,” like a Sierra 69gr MatchKing. 1-8 will stabilize any of the newer heavier bullets intended for magazine-box cartridge overall lengths, like a Sierra 77gr MatchKing. An 8 twist will also shoot most of the longer, higher-BC profiles, like the Sierra 80gr MatchKing (which is not intended to be assembled into a round that’s loaded down into a magazine).
Other popular calibers have likewise edged toward faster and faster “standard” twist rates, and that includes 6mm and .308. Once those were commonly found as 1-10 and 1-12, respectively, but now there’s more 1-7s and 1-9s offered. Reason is predictable: longer and heavier bullets, and mostly longer, have likewise become more commonly used in chamberings like .308 Winchester and 6XC.
The tell-tale for an unstable (wobbling or tumbling) bullet is an oblong hole in the target paper, a “keyhole,” and that means the bullet contacted the target at some attitude other than nose-first.
Base your next barrel twist rate decision on the longest, heaviest bullets you choose to use, and at the same time realize that the rate chosen has limited those choices. If the longest, heaviest bullet you’ll shoot (ever) is a 55-grain .224, then there’s honestly no reason not to use a 1-12. Likewise true for .308-caliber: unless you’re going over 200-grain bullet weight, a 1-10 will perform perfectly well. A rate that is a good deal too fast to suit a particular bullet may cause damage to that bullet (core/jacket integrity issues), and I have seen that happen with very light .224 bullets, like 45-grain, fired through, say, a 1-7 twist. At the least, with that great a mismatch you might not get the velocity up where it could be.
Bullet speed and barrel length have an influence on bullet stability, and a higher muzzle velocity through a longer tube will bring on more effect from the twist, but it’s a little too edgy if a particular bullet stabilizes only when running maximum velocity. My failed 90-grain .224 experiment is a good example of that: I could get them asleep in a 1-7 twist 25-inch barrel, which was chambered in .22 PPC, but could not get them stablized in a 20-inch 1-7 .223 Rem. The answer always is to get a twist that’s correct.
Effects on the load itself? Yes, a little at least. There is a tad amount more pressure from a faster-twist barrel using the same load, and the reason is initial bullet acceleration is slower.
Here’s how to use (or not use) Standard Deviation calculations in ammo decisions, what they are, and aren’t… Keep reading…
A standard deviation plotted out is a bell curve. Chances are outstanding that a range session calculation will plot into what they call a “normal curve.” Like any normal bell curve, it can get divided into three segments and given values, and, technically, these are the “standard deviations.” It’s “a” standard deviation rather than “the” standard deviation.
Assuming a normal curve, the values are that about 68 percent of forecasted results will lie within one standard deviation of the mean, about 95 percent lie within two, and over 99 percent lie within three standard deviations. If we have an SD calculated to be 12, that means that applying one standard deviation means that about 68 percent of all “next shots” will be +/- 12 feet per second. Since, though, the curve is in threes, in effect if not in fact, that means that a scant number of the shots pose a chance for +/- 24 and some teeny chance remains for shots to go to +/- 36. That, however, is extrapolating or predicting with data and that’s not really wise and doubtlessly uncalled for. Data collection is a record of numbers and I do know that there’s 100 percent chance that the highest and lowest velocities collected for an SD calculation did, in fact, happen. That’s what matters. No matter what the shot results calculated into for an SD, those were the two that represent the highest and lowest prints on the target.
It’s mathematically not possible for an SD to be higher than the greatest single raw deviant, but I do for a fact know that an SD can easily be far lower than the worst shot. Given how it’s calculated, along with how many samples contributed, it’s plain that the nearer the majority are to themselves the less impact a bad one or more has.
I said in a very open-ended way last article that a tolerable SD is 12. Anything more than that is not good; anything less than that probably won’t perform noticeably any, if at all, better than a 12. However! It is at this number, so I say, where the often-uttered tune of “…SD doesn’t matter…” and its refrain of “…seen good accuracy with high SDs…” starts and stops. Twelve. That’s it. Now we have an SD that “doesn’t matter.” The reason this is stuck out here is that everyone has heard this chorus but hopefully figured that it couldn’t be taken universally at literal value. Well it can’t. So now you know! It’s 12. 12 should not be responsible for a points loss, even accounting for or including coincidence of any one shot hitting the edge limit of usual group size.
(Yes, 13 or 14 or 16 or even 20, which is often given as a “limit,” might well be a realistic ceiling but I drew a line to have one. Since there’s a line, now we can cross it and commence argument. I won’t use any load in competition that wouldn’t calculate to a single-digit SD. My 600-yard .223 Rem. load tested to an SD of 3.18 with a Range of 8 fps.)
So after all this has been said, I don’t give SD as much weight in my load decisions as some do. The reason for my focus on it here, as said in the first article, is because that’s the usual “standard” measure of consistency. I look at the speeds as they come up on the chronograph display and write them down. I weigh range and extreme spread more heavily, and I want to see really small variations over the number of test rounds I fire. It’s a matter of waning patience and waxing time. If I see a variance that could cost a point, that load is abandoned.
If you don’t have a chronograph or don’t want to burden a testing session with using one, watch for a correlation between the elevation dispersion and the wind dispersion of test groups. At 600 yards I always test from position (prone, “suited up”). No chronograph (muzzle-mounted chronographs now make this a non-issue). I’ll already have speed-checked the load I’m now down on the mat with. When I shoot my groups, I honestly don’t pay much attention at all to anything but measuring how level I got my perforations. Attempting shot-to-shot wind corrections when testing for ammunition accuracy throws another variable into it that might be most misleading. If I come up with a group that’s a foot wide but only three inches tall, I’m happy.
5 TIPS FOR LOWER SDs
Aside from finding the perfect and magical load combination, ha, there are a few things that do seem to help tighten shot-to-shot velocity deviations. They’ve all be talked all the way through and back again in this space in other articles, but, considered ultimately that this is the overall effect they have, here they are again:
One.Primer seating: fully seated onto a flat pocket bottom.
Two.Consistent propellant charge: weigh the charges if metering isn’t dead-on perfect.
Three.Ignition efficiency: consider that inside flash hole deburring routine…
Four.Temperature insensitivity: choose propellants that exhibit stability under extremes.
Five.Balance: strive to find a propellant that fills the case, but “loosely” (no compressed charges); even more, avoid an overage of air space. These both allow too much variance in ignition pattern.
Addition I learn things all the time. A most knowledgeable and helpful reader pointed out a detail in SD calculation that is better adapted to calculations for ballistics, and it helps because of the usually relatively small size sample involved. We’re not going to chronograph 100s of rounds, usually 10-20. So, instead of dividing the average square of the deviations by the number of samples, but the average square of the values, less one (n-1). That helps any distortion of results toward a number that calculates too small. Keep in mind always that SD is an estimate, in one way of looking at it.
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