A few factory “tricks” can be applied to handloads, if you feel a need. READ MORE
Last time we took a look at some of the differences between factory-loaded ammo and our own recipe handloads. That material wasn’t a total indictment on factory ammo as might have been expected coming from me and directed toward mine, and that’s because there are some times ready-made has its place.
One of the main-most good things that can be said about factory ammo is that it has a shelf life that, given decent storage conditions, will likely exceed that of handloads. Or not. “Not” depends on what steps or processes were applied to the handload.
The main culprit in decreasing stored life of a loaded round results from corrosion. Some call it “sticktion,” and I’ve had it happen a few times. What it is, is the case neck and bullet corrode — stick — together. That will elevate pressure. I had a rash of blown primers from the batch I used.
There are a few ideas on how to reduce or eliminate stiction, and the first starts with eliminating the catalyst for the corrosion. Don’t touch the bullets with your bare fingers! Don’t touch the cases either. I know a few commercial loaders who produce precision ammunition and they’re all about surgical-style gloves.
I have run some tests using bullet sealant (applied as a liquid then UV-cured) and such a product will, indeed, virtually eliminate any worries over corrosion. Most factory, and virtually all mil-spec, ammo uses some formulation of sealant (bullets and primers). The reason I tried it, though, was because of the promise of greater accuracy. Glued bullets tend to produce from a little to a lot smaller velocity spreads. My jury is still out on the value of this additional step, and when there’s a verdict I’ll let you all know how it played out.
There are a few different bullet and primer sealers available. For the most part, these are fairly easy to apply and none are what I’d call expensive.
Giving loaded rounds a good cleaning, and then storing them at the least in air-resistant boxes, keeps the shine on and the corrosion away for a good long while.
Some run their loaded rounds in a routine-type case cleaner, like a vibratory tumbler. That’s all good, but I suggest not using anything but “pure” media to ensure that no residues are left behind.
I use denatured alcohol and a bath towel: place the rounds on half the towel, pour on the alcohol, fold over the towel and roll the rounds around. Let them dry and box them up.
Handling precautions during round assembly and then good storage afterward extends the shelf life of reloads.
More about another factory trick — crimping — next time.
The preceding is a adapted from information contained in from Glen’s books Top-Grade Ammo and Handloading For Competition. AvailableHERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.
There are a few tricks and treats, and traps, in reloading press designs and associated pieces-parts. Shellholder first. KEEP READING
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.
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.
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.
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.
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. AvailableHERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.
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
[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.
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.
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.
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.
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.
Five tips to reduce shot-to-shot bullet velocity deviation. READ MORE
I’ve spent the last two editions on velocity variations, and this one will offer some ideas on how to get yours as low as possible.
Consistent Propellant Charge
This comes first to mind, and probably comes first in most everyone’s mind, and that’s because it makes the most “sense.” Sure enough, given the effect on velocity from a tenth or two grain variation in propellant, eliminating that variable clearly takes a big step toward improving consistency.
Now comes the big question: Throw or weigh? That one there is another complete article, but the short course is, “it depends.” Bad answer! I know, but there’re more coming in a bit to add to either confusion or clarity, depending on experience. Overall, I’ll say “weigh.”
I say “weigh” because that goes a long way toward eliminating inconsistent amounts of propellant as a factor. I also say weigh because of the previously mentioned undeniable effect of haphazard propellant levels, and weighing each charge should eliminate that. Do, however, make sure that the scale is reliable. I still use an old-school beam scale. A good deal of trials and tests have not given me the confidence I need to have in many electronic scales. The short answer to satisfaction, again from my experience, is that you’ll likely get best, or at least better, results from a scale that ranges upward in cost from the “mid-priced” units, and decidedly better performance compared to the lower-priced models. I’ll also say the same for the scale-based dispensing devices on the market. I’ve used a couple that my meter beat, and a couple that were impressively accurate over a lengthy session.
Numbers 2 and 3 on my 5-point list involve the primer — ignition. This is a crucial point in the life of a flying bullet. If the primer is delivering a consistent flash to ignite the propellant column, then said column will ignite more consistently.
Uniforming the primer pocket can help. The main thing this trick accomplishes is a flat-bottomed primer pocket. The tool faces the bottom of the pocket to squareness and also cuts the entire bottom of the pocket to squareness. Most primer pockets are formed using a punch and that leaves a radius on the “corners,” resulting in a bowl-shape. Since primers are flat, they don’t seat correctly and as designed unless the primer pocket is flat. And, if the primer pocket is flat then the primer can be seated fully, which means that the anvil “feet” make correct, full contact.
If the primer isn’t seated flat and flush then some energy from the firing pin gets absorbed in finishing the primer seating, and that leads to a softer hit, and less (perfect) consistency in ignition. Yes. It’s tiny, but so is all of this!
Uniforming the primer flash hole is another trick that honestly “works” to improve velocity consistency. This is another usually punched process and can leave a burr visible on the inside of a case. A uniforming tool removes this burr and, depending on the tool design or its adjustment (if possible) will also create a little funneled area believed to better spread the initial flash to ignite the powder column. Some worry about losing metal in this area, but it will not weaken the case in any detrimental fashion.
Consistent Bullet Grip
Bullet “release” has to be consistent for the combustion behind it driving it forward to be consistent. First, that means the case neck walls should ideally be consistent so the case neck cylinder will be sized to a consistent dimension. The “spring back” in brass means thinner or thicker walls respond differently to the same dimension sizing apparatus. Again, this is a tiny thing, but they all add up.
Further, myself and a good many others have found that we usually see better shot-to-shot velocity consistency with a little more, not a little less, case neck grip, or bullet retention, however you prefer to call it. By “grip,” which some also often call “case neck tension,” I’m talking about the difference between the sized case neck inside diameter and the bullet diameter. This is something that my friend and associate, David Tubb, has done a good deal of experimentation with, as have I.
We both found that best results, again meaning best velocity consistency, came at more than 0.002 inches difference. I routinely use 0.004 for my competition loads.
One way to improve the consistency in grip is using a mandrel as a separate operation. A mandrel is pretty much a sizing button or expander that’s got a longer surface area, and, of course, is precisely sized. The idea is to use the mandrel on a case neck that is sized at least 0.003 inches smaller than the mandrel, run the mandrel into the case neck for a 5-count (important) and then withdraw it.
Another thing: I’ve got all the means but not yet had the time to experiment with adhesives. Right: That’s glue between the bullet and the case neck inside. Varying bond-strength glues have been used in honking big cartridges for military use for years and one of the pretty well demonstrated benefits is increased velocity consistency. This is a new area for the handloader and I hope to have some more information about it later on.
I really don’t like it when we sometimes (and honestly) say that it’s “more art than science.” We say that when there’s a predictable or at least reproducible combination of things that give great results. In handloading that’s something like very good accuracy and very small shot-to-shot velocity variations.
Of course it’s science! But it’s just not that well understood, meaning it’s not precisely predictable, or at least not by me and most who recite that mantra. There is a combination of case, propellant, primer, bullet, and barrel that appears magic compared to some of the other things we’ve tried. It’s all a system. Since we’ve got the barrel and it is what it is, propellant and primer are the main variables, and of course we can try different cases. I believe that it’s case volume as part of the system that has its influence on performance.
Back to the first point, ultimately the answer to the “throw or weigh” question comes as a combination of the precision of the meter and the choice of propellant. I don’t weigh charges, or not making up the loads I settled on for use in tournaments, and that’s because I see zero difference in on-target results, and that starts with seeing zero difference in shot-to-shot velocity readings in testing. I, however, have seen radical differences in on-target results with other combinations comparing weighed and thrown. However! Those loads still didn’t make my cut because, overall, the velocity consistency just wasn’t there in the first place. Folks I can tell you absolutely that just weighing each charge does in no way mean you’re going to get suitable spreads with any old gunpowder. The ultimate answer to attaining tiny shot-to-shot velocity variations, and tiny shot groups, comes from experience in doing your own testing. That’s a “said nothing” statement, but there has to be a willingness to experiment.
Beyond only experimentation, though, I think these few tips will help ensure you’re getting the best that combination can give you.
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
There are a whopping lot of propellants on the market. How do you choose one? Well, usually it’s more than one… READ WHY
All we ever really want is a propellant that provides high consistent velocity, small groups at distance, safe pressures over a wide range of temperatures, and burns cleanly, and, of course, it should meter perfectly. Dang. I know, right?
Ultimately, propellant choice often ends up as a compromise and it may well be that the smallest compromises identify the better propellants. Getting the most good from your choice, in other words, with the fewest liabilities.
There are two tiers of basics defining centerfire rifle propellant formulas. The granule form can be either spherical (round granules) or extruded (cylindrical granules). Next, the composition can be either single- or double-base. All propellants have nitrocellulose as the base; double-base stirs in some nitroglycerol to increase energy.
There’s been a good deal of effort expended and applied over the past several years to reduce the temperature sensitivity of propellant. Coatings come first to mind, and I use nothing but these “treated” propellants.
This attribute is very (very) important! It’s more important the more rounds you fire throughout a year. A competitive shooter’s score hinges on consistent ammunition performance. Test in Mississippi and then go to Ohio and expect there to be some change in zero, but a change in accuracy or a sudden excess of pressure and that’s a long trip back home. It’s common enough for temperatures to (relatively speaking) plummet on at least one day at the National Matches, so my 95-degree load has to function when it’s 50.
Some are decidedly better than others in this. There are several propellants I’ve tried and will not use because I didn’t get reliable results when conditions changed. Some gave outstanding groups on target, on that day, at that hour, but went goofy the next month when it was +20 degrees. Heat and cold can influence pressure in a sensitive propellant.
Single-base extruded (“stick”) propellants are my first choice. A good example of one of those is Hodgdon 4895. These tend to be flexible in maintaining performance over a wider range of velocities, related to a wider range of charge weights. For instance, I’ll vary the charge weight of the same propellant for ammo for different yard lines. I’m reducing recoil or increasing velocity, depending on what matters more. Zero and velocity are different, but accuracy doesn’t change.
Spherical or “ball” propellants (these are double-base) are a good choice for high-volume production, and also tend to be a great choice for highest velocities at safe pressures. These meter with liquid precision. They, however, tend to be less flexible. That means they tend to work best at a set and fairly finite charge and don’t do as well at much less or more than that, and especially at much less than that. More in a minute.
Double-base extruded propellants (sometimes called “high-energy”) do, yes, produce higher velocities at equal pressures compared to single-base but also tend to be less flexible and exhibit performance changes along with temperature changes. Vihta-Vuori and Alliant are the best known for their formulations in these. Double-base usually burns at a hotter temperature (not faster or slower, just hotter) and can increase throat erosion rate. Some double-base spherical propellants claim to burn cooler. I’m not certain that this is a huge selling point, either way, for a serious shooter, but, there it is.
All propellants are ranked by burning rate. That’s easy. That’s just how quickly the powder will consume itself. All reloading data manuals I’ve seen list propellant data in order from faster to slower. For instance, if you’re looking at .223 Remington data and start off with tables for 40-grain bullets, you’ll see faster propellants to start the list than you will moving over to the suggestions for 75-grain bullets.
It’s tough to find a perfect propellant for a wide range of same-caliber bullet weights. Faster-burning propellants tend to do better with lighter bullets and slower-burning tends to get more from heavier bullets. That’s all about pressure and volume compatibility. Again, I have found that a single-base extruded propellant will work overall better over, say, a 20-plus-grain bullet weight range than a single choice in a spherical propellant.
The idea, or at least as I’ll present my take on it, is that we want a fairly full case but not completely full. I don’t like running compressed loads (crunching a bullet down cannot be a good thing), and excessive air space is linked to inconsistent combustion. We ran tests upmteen years ago with M1As and found that out. Many details omitted, but here was the end: Settling the propellant back in the case prior to each shot absolutely reduced shot-to-shot velocity differences (the load was with a 4895, necessary for port pressure limits, and didn’t fully fill the case).
Generally, and that’s a word I’ll use a lot in this (and that’s because I know enough exceptions), spherical propellants have always performed best for me and those I share notes with when they’re running close to a max-level charge. More specifically, not much luck with reduced-level charges.
Too little spherical propellant, and I’m talking about a “light” load, can create quirky pressure issues. Workable loads are fenced into in a narrower range. This all has to do with the fill volume of propellant in the capped cartridge case, and, as suggested, that’s usually better more than less. That further means, also as suggested, there is less likely to be one spherical propellant choice that’s going to cover a wide range of bullet weights. That’s also a good reason there are so many available.
With some spherical propellants, going from a good performing load at, say 25 grains, and dropping to 23 can be too much reduction. One sign that the fill volume is insufficient is seeing a “fireball” at the muzzle. Unsettling to say the least.
Spherical propellants also seem to do their best with a “hot” primer. Imagine how many more individual coated pieces of propellant there are in a 25-grain load of spherical compared to a 25-grain charge of extruded, and it makes sense.
However! I sho don’t let that stop me from using them! I load a whopping lot of spherical for our daily range days. We’re not running a light load and we’re not running heavy bullet. We are, for what it’s worth, running H335.
So, still, how do you choose a propellant? Where do you start? I really wish I had a better answer than to only tell you what I use, or what I won’t use. There are a lot of good industry sources and one I’ve had experience with, including a recent phone session helping me sort out Benchmark, is Hodgdon. You can call and talk with someone, not just input data. Recommended.
When it’s time, though, to “get serious” and pack up for a tournament, I’m going to be packing a box full of rounds made with a single-base extruded propellant that meters well. As mentioned before in these pages, I have no choice in that, really. I’ll only run the same bullet jackets and same propellant through the same barrel on the same day. I need a propellant that works for anything between 70- and 90-grain bullets.
With time comes experience, and I know I sure tend to fall back on recollections of good experiences. I admittedly am not an eager tester of new (to me) propellants. I have some I fall back on, and those tend to be the first I try with a new combination. There are always going to be new propellants. That’s not a static industry. I may seem very much stuck in the past, but I no longer try every new propellant out there. I like to have some background with a propellant, meaning I’ve seen its results in different rifles and component combinations. Mostly, I ask one of those folks who tries every new propellant…
There is a lot of information on the internet. You’re on the internet now. However! There’s also not much if anything in the way of warranty. If you see the same propellant mentioned for the same application a lot of times, take that as a sign it might work well for you. Do not, however, short cut the very important step of working up toward a final charge. Take any loads you see and drop them a good half-grain, and make sure the other components you’re using are a close match for those in the published data.
One last: Speaking of temperature sensitivity: Watch out out there folks. It is easily possible for a round to detonate in a rifle chamber if it’s left long enough. Yes, it has to be really hot, but don’t take a risk. A rash of rapid-fire can create enough heat. Make sure you unload your rifle! Here’s an article you might find interesting.
An ideal case trimmer provides precision, speed, and affordability. Here are some ideas on avoiding compromise. READ MORE
At some point, or points, cases need to be trimmed to a shorter length. Brass flows. Therefore, a case trimmer is pretty much a given in the tool assortment for any handloader.
There are needs and wants, realities and ideals. That’s true with many things, and applies often to reloading equipment. Ideally, a case trimmer will go beyond just trimming the case to a shorter length. They all do that well enough. I think it’s important that a case has a square mouth — dead flat across the top. This is an asset to getting a bullet started well into the case neck during the seating operation.
A Good Trimmer
There are a variety of trimmers available from most of the popular industry tooling suppliers. And most follow a pretty similar form and formula: a little hand-cranked lathe. In these, the back end of the case is chucked into a collet-type fitting. A caliber-size pilot that’s centered in and surrounded by a cutting head goes into the case neck and supports the front of the case.
Not nearly perfect! There are a few reasons and sources for reduced precision. The tool alignment may be true at each “end” of the trimmer, but the case we’re working with probably isn’t true. Mostly, since there has to be a gap for the pilot to freely rotate, and since case neck walls aren’t all consistent in thickness, the fit isn’t close enough to prevent out-of-round rotation. Along with the inevitable case body warp there’s bound to be a tad amount of wiggle. Since the case is supported only at its head area, not by its body, there’s flex afoot.
None of that means the case neck won’t get trimmed to a shorter length, which is the general idea. It does, however, mean that it’s not liable to be perfectly squared up.
A Better Trimmer
I rarely just overtly recommend one tool over all the others, but after a good many years working with case trimmers, I can and will tell you that the LE Wilson design is the best I’ve yet tried. I guess, yes, that is just opinion, but it’s really not.
The difference in this trimmer design is that the case is supported within a sleeve by its body. There’s no polarized suspension front and back. Mostly, there’s no pilot. The cutter on an LE Wilson faces off the front of the case squarely. The sleeve holding the case sit atop a pair of rails and the whole arrangement excludes case condition from the process.
So why doesn’t everyone use one? Honestly, I’m not entirely sure. It is a different arrangement, and it’s not cheap, especially not if you accessorize the fool out of it with a stand, a clamping device, and a micrometer. It’s not more than the other higher-end manual trimmers though.
It’s also fast! There’s no clamp-twisting to get the next case in place, and back out again. The sleeves are slightly tapered inside so the case is tapped in and then tapped out. With a little experience it’s amazingly quick to get through your block full of brass.
Virtually all case trimmers can provide additional utility, do different jobs. The cutter can be replaced with a reamer, and some can get reworked into outside case neck turners.
My choice is usually a stand-alone station, and that’s mostly because it’s pretty tedious refitting the appliances. I am, or at least have become, lazy.
As with all said about alignment for case length trimming, that is also all the same for using a trimmer for other chores. And, yes, I still think the LE Wilson works best as a reamer, for instance, and that is because all the alignment precision is built into the tool itself; the case doesn’t play a role.
About options, by all means fit up a “combo-head” if it’s available that will finish the trim with a nice inside/outside chamfer/deburr. Big time saver. These can be a trick to get set just right, but it sure saves time.
It sure is nice to get a break from the crank! There are, though, as I see it, two kinds of power case trimmers. Those that replace the hand crank with an electric motor and those that are designed from the start to be powered.
Some trimmers offer a means to add your own power source, like an electric screwdriver or drill.
My favorite proprietary power trimmer is a Gracey “Match Prep.” Designed by the late Doyle Gracey as a fast and easy way to trim huge quantities of Lake City brass for NRA High Power Rilfe shooters, it’s a serious machine. It works like a gigantic electric pencil sharpener, at least in spirit. Pick up a case and push it forward into a collar and it’s trimmed and squarely faced. No clamps or sleeves. The case shoulder stops against the inside of the collar, so it’s imperative that all cases are resized prior to use. As said last time, though, that’s really the only time you’ll get consistent results with any trimmer.
I don’t know how many cases I can trim in an hour because I’ve never spent an hour using a Gracey. I can easily do 100 in under 5 minutes.
Another very good power trimmer is the Giraud. Its essential means for and in operation are about the same as Gracey but it is a nicer package with more features. Gracey is pretty daggone simple. That’s not all bad. I’d say Giraud is the best, and its price does reflect that.
Again, it’s important to evaluate the overall condition of a batch of cases, related to how many uses they’ve had. Having grown a little longer isn’t likely to be the only thing that’s changed in a case that exceeds whatever limit you set for it.
And, speaking of, the “trim-to” length is usually 0.010 inches shorter than the maximum SAAMI-stated overall case dimension.
Next time we’ll look at tools used to treat the trimmed case necks and finish this task in fine style.
We all have to trim bottleneck cases sometime. Question is when and how much, and then “how,” and here’s a place to start. KEEP READING
After going through that last series on keeping up with changes in cases resulting from their use and reuse, “flow” was a culprit behind the majority of detrimental changes. That is: Brass flows during firing. It moves from where it was to somewhere else. Since there’s a finite amount of material in a case, one place is getting thinner and another is getting thicker. The sources of the material, where the flow starts and where it stops, are primarily case necks and case heads.
To completely finish up on all this, the most obvious indication that there’s flow is measuring case lengths from base to mouth.
First, and very (very) important: The ONLY time to check case length, or to trim cases, is after they have been sized! A fired, unsized case will be shorter than it was going in. The reason is because of the expansion in the case that resulted from firing. When the expanded areas are squeezed back to spec by a sizing die the case gets longer as it gets smaller in diameter, same as rolling a ball of modeling clay out on a table. After sizing is also the only time we can we know that the case shoulder area is consistent in dimension.
You’ll see two length figures published for your cartridge of choice: maximum length and trim-to length. Published trim-to length is usually 0.010-inches under what’s listed as maximum.
I got a gage umpteen years ago that could indicate the maximum case length a chamber could accommodate — technically, a “chamber length gage.” Man. I checked the chambers in my main rifles and found that they were all well more generous than the SAAMI-maximum. That didn’t really mean a lot, in fact, to how I proceeded. And it also didn’t mean I can advise ignoring the potential for danger in exceeding SAAMI-maximum. It just pointed out that there are differences in chambers, gun to gun, and at least showed me that not exceeding max stated length should easily keep you safe.
If a case got too long, exceeded the amount of room given to it in the chamber, that would be a safety problem! The bolt may not close fully. And, if it did, the extra length would create a pinching-in constriction, and that would spike pressure.
We can easily imagine that there’s an influence from relatively longer or shorter case necks in their influence in consistently encasing the bullet. And I’m sure we’d be right. Trimming cases all the same should mean that all the case neck cylinders are the same height. Someone looking to maximize accuracy is liable to get worked up about that enough to trim each firing. I trimmed my tournament cases each use. And, no, none were remotely approaching maximum length. It’s reasonable to further suppose that more or less retention will influence velocity consistency.
Another performance asset may or may not happen, depending on the trimming tool chosen. But. A good trimmer will square the case mouth. I’ve seen a many new cases with a “half-moon” cut after trimming. A square case mouth helps a bullet start and finish straight when it’s seated.
My routine for this sort of “accuracy-oriented” case trimming is simple — tedious, but simple. I don’t measure each case. I just run them all through a trimmer set to “some” length. Some are trimmed more or less, some just show a bright scuff on one little bit of the case mouth, but they are then all the same length. If I can’t prove it in group sizes, it sho does set my mind at ease that all the cases are holding all the bullets more nearly the same.
For those rifles that aren’t tournament guns, the only concern is that none, indeed, become too long. Those I will check at that “4-firings-in” point. Some may have reached SAAMI-maximum, most won’t have, but all will be longer than when started. I start them at a figure close to suggested “trim-to.” Stop and think about it, and if there’s been overall a 0.010-inch length increase, that’s significant.
As with all things associated with use and reuse in semi-autos compared to bolt-actions, cases are going to grow more and faster in a gas-gun.
Another instance where it’s important to keep up with case lengths, and that, again, really has to do with making them all the same, is for those who crimp (with a conventional cannelure method).
Now, there’s zero harm in using a longer “trim-to” length, and that may be more popular than my method. These lengths are stated in reloading manuals. Keeping up with it over years, I’ve seen no difference in the rate of lengthening trimming longer or shorter; I trim “shorter” solely as a matter of consistency over the (short) life of my semi-auto cases.
Yikes. Gremlins. Case neck “donuts” are a common development in an aging cartridge case, and it’s often unknown. Read this and know! MORE
Even if the case neck passes the “drop test,” there might be something amiss within that cylinder, and it might not show up until after case sizing, and that is the “dreaded donut.”
What exactly is a case neck donut? It’s a tiny elevated ring of brass on the interior circumference of the case neck, right at the juncture of the case neck, case shoulder. It is pretty much a little o-ring, in effect.
This “tight spot” reduces the case neck inside diameter at that point, which will, not may, have an influence on the amount of constriction surrounding a seated bullet. And since it won’t be perfectly consistent from case to case, accuracy will, not may, suffer.
And, without a doubt, there’s going to be cartridge pressure changes, which can create velocity changes. A donut is not likely to create anything like a pressure spike similar to what an excessively thickened (overall) case neck can, but it can’t be a Good Thing no matter what.
Now. I can’t say this is always a symptom of aging cases (based on the “four firings in” idea I’ve been running with). I’ve seen donuts in new cases. However, in my experience with the brass I normally use, and, therefore, that which I have the most notes on, the formation of a donut seems to coincide at the same time I measure what I think is excessive case neck wall thickening. Again, though, I spent an afternoon at the loading bench with David Tubb trying to solve donut issues he was having after one firing on commonly known “good” brass. We solved them, and more in a bit.
There is a difference in the case wall tubing thickness at the case neck, case shoulder juncture. The neck walls are a consistent thickness — it’s a parallel cylinder (or they start off that way). At the shoulder wall thickness increases steadily in a taper as it goes down the case shoulder to then intersect with the case body walls.
There is diverse speculation about exactly what causes or creates the donut. My own experience suggests that there can be more than one factor or influence. But at the root of it is simply this difference in wall thicknesses. The difference has an influence in this area with respect to brass flow. Seems certain that there’s material movement forward from the case shoulder.
If that’s it, then the chamber dimensions (neck diameter and headspace) and cartridge case headspace play their parts. Same old: with respect to case headspace, it’s another reason to set back a shoulder the minimum amount needed for faultless function. Also old news: that’s going to be more for a repeater than a single-shot, and well more for a semi-auto.
I’ve seen it said that the expander ball or sizing button coming back up through a sized case neck “drags” the metal up with it, but also I know without a doubt that sizing without an expander means there’s a more pronounced donut. Checks I’m made sizing with and without an expander (using a neck-bushing-style die), show that an expander or, my preference, an expanding mandrel, reduces the donut influence. That, by the way, is from selecting bushings that produce the same case neck outside diameter with and without the inside neck sizing. I think the expander is just pushing it to the outside… But that’s good!
This one is pretty easy, after a little math at least. The most direct means is using a correctly sized reamer on a likewise correctly sized case neck, and that’s where the math comes in. The reamer should be the diameter of your sized neck inside diameter; that will pare away the donut without changing the case neck wall thickness. The idea is to get the donut without universally thinning the case neck walls, and the reason there is maintaining consistency. That, after all, is why we’re doing any sort of fixing on cases in the first place: get the same performance the maximum number of firings.
Another way, which is primarily preventative, is with an outside case neck turner, if its cutter has an angle or bevel (see photo for example). Turn down onto the case shoulder about 1/16 of an inch. Do this on new cases since that’s the only good time to turn case necks. This area is then “relieved” enough that the donut won’t form, or not for a while. In firing, this thinned area essentially relieves itself. I got this tip from Fred Sinclair eons ago and it’s the only thing I know of that heads off the donut. If you are worried about weakening a case in this area, don’t do it, but I can tell you that’s a moot worry. It’s very common practice among competitive Benchrest and NRA High Power Rifle long-range shooters. That’s how we came to a quick and permanent (well, for the short life of those cases) solution to David Tubb’s donut problems with a 6mm-.284.
Short aside note that’s being revisited from other articles I’ve done here, but the VERY BEST way to never worry about donuts is to never seat a bullet into this area! That is the reason the better (in my mind) cartridge designs feature long necks.
Glen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com
Cartridge cases always fail on the “next firing.” Question is which one that might be. Need to know! KEEP READING
I’d always rather say it all at once, but the realities of tolerance, and space, sometimes mean I have to split a bigger topic into smaller installments. The “tolerance” part is how many pages you all are willing to scroll through!
This multi-part topic is when, and then how, to check after the progress of changes commencing with the firing on a new case. It’s the “progress of degeneration,” in a way of looking at it because the concern is getting a handle on when enough change in the brass has come about to require attention. Or abandonment. As said then, for me that’s 4 firings. That, as said last time, is when I might see changes that need attention. Also as said, that figure didn’t come out of a hat, but from my own notes in running my competition NRA High Power Rifle loads.
The areas most affected are the case neck and case head area. Case neck walls get thicker, and that was the focus last time. Well, the case head area body walls get thinner. Primer pockets get shallower and larger diameter.
As started on: Brass flows during firing. It expands, then contracts, and when we resize the case, it contracts, then expands (a little). This expansion and contraction makes the alloy harder over the entire case, but with more effect in areas of more expansion, and flow. Replace “hard” with its effect, “brittle,” and that’s a clearer picture. This increasing hardness influences its reaction to being sized or otherwise stretched. As with many metals, bend it back and forth enough times and it will break. It will also fail if it loses enough resilience, or thickness, to withstand the pressures of firing.
When a case is under pressure during firing, the brass, like water, flows where it can, where it’s more free to move. Of course, the chamber steel limits the amount it can expand. The case shoulder blows fully forward and the case base is slammed back against the bolt face. There is, therefore and in effect, a tug on both ends — it gets stretched. The shoulder area is relatively free to expand to conform to the chamber, but the other end, the case head area, is not. Since that’s the area of the case with the thickest walls, it doesn’t expand “out” much at all. What it does is stretch.
The “case head area,” as I refer to it here, is the portion of the case above the web, which is just above the taper that leads in to the extractor groove. The “area” extends approximately an eighth-inch up the case body.
That portion of the case does not fully expand and grip the chamber, but the area immediately ahead of it does. So the case body expands and grips the chamber, and that last little bit back to the base can and does move. It stretches. If you see a ring circling the case, noticeable because it’s lighter color than the case body, and it’s in this area, I’d say that case is done. The ring will be evident after firing, not after; don’t confuse a shiny ring around the case in this area with what can be normal from sizing, especially if it’s been a hotter load. That is pretty much a scuff from the sizing die squeezing down this expanded area.
And that’s right where a “head separation” occurs. It can crack and also blow slap in two, and that’s the “separation” part of case head separation.
This is a spot to keep close watch on as cases age. It is also the area that is more “protected” by sizing with less case shoulder set-back. That is, pretty much, where the freedom for the stretching movement in this area comes from (the case shoulder creates a gap). However! As said many a time, semi-autos need some shoulder set back for function, and it’s the reason to use an accurate gage to determine the amount of set-back needed.
Some folks unbend a paper clip and run it down inside a case and drag it up against the inside case wall as a sort of antenna to see if they detect a dip-in near the head area, which would indicate that the wall in this area has been stretched thinner. If there’s enough to feel it, that case is done.
Since I’m working off this “4 Firings In” checklist, if you’re seeing a sign that a head separation might be nigh in that few uses, chances are the shoulder set-back is excessive, and also too may be the load pressure level.
Another case-head-area and pressure-related check is the primer pocket. As said, the primer pocket will get larger in diameter and shallower in depth each firing. As with many such things, the questions are “when” and “how much,” and the main thing, “how much?”
If the pocket gets excessively shallow, and that’s judged by a primer that seats fully but isn’t at least a tick below flush with the case base, there could be function issues. There’s a risk of a “slam-fire” with a semi-auto that uses a floating firing pin, and, if there is actual protrusion, that has the same effect as insufficient headspace.
Shallower can be refurbished. That’s a primary function of a primer pocket uniformer. Larger diameter, though, can’t be fixed. I’ve mentioned in another article or two that, any more at least, my main gauge of load pressure has become how much primer pocket expansion there’s been. I judge that without using the first gage, well, unless my primer seater is a gage. If a primer seats noticeably easier, that’s the clear clue that the pocket is too big. Another is seeing a dark ring around a fired primer, indicating a little gas leakage.
Measuring primer pockets is a waste of time, say my notes at least. First, it’s not easy to accurately (truly accurately) measure a pocket, especially its diameter, but, that’s not really what matters. It’s how much grip there is to maintain the primer in place during firing.
I pay close attention to resistance in primer seating and won’t reuse a case that’s too easy.
Good deal on what I think is good brass, especially if you’re an AR15 loader — HERE
Glen’s books, Handloading For Competition and Top-Grade Ammo, are available at Midsouth HERE. For more information about other books by Glen, visit ZedikerPublishing.com
Along with all the other operations we do to them, cartridge cases also need maintenance. A good question is “when”? That’s next… KEEP READING
I tend to write much of what I do for those who reload for production. Those are folks expecting good utility in exchange for the expense and effort: a reliably-performing round of ammunition, over and over again. They’re loading and reloading because they like to shoot. It’s a big bonus to most, and I include myself in this group most of the time, if that good performance comes with a minimum of effort. Clean, size, prime, fill, seat, shoot. Five steps to get to the one thing that matters most: shoot! I am also in another group some of the time, not as often now as I once was, and those folks may add a few more steps before getting to the “shoot” part (case prep mostly).
It would be wonderful if that simple cycle endured without end. But it won’t.
Overall case condition after X-many firings varies A LOT because of a lot of factors, variables. What matters is getting a handle on it. I look over each case each time I load it, but I don’t break out the measuring tools. That’s not neglect. There is never (ever) any excuse for neglect. That’s not what this is about. It’s about working out a responsible, reasonable, and realistic schedule for when to take a close look at the progress in condition that new batch of cartridges cases has followed after some time.
In my experience, which is what’s in my notes, I say that’s 4 firings.
I went through the per-use checks enough times to know the schedule one brand and lot of brass, used with the same loads in the same barrel, follows with respect to changes. And by that I mean when changes require attention. I’m also starting with prepped cases, including trimming, before their first firing.
Let me make clear that I’m not suggesting that 4 firings is maximum case life! What I am suggesting is that this is the point where it’s likely to see measurable influences from use and reuse, and, as such, that it can be measured. That’s what we’re after now: take a check to see what’s happening, and that also is a big help toward getting clues about where and when these changes might get noticeably influential.
So, to be clear: the case has been fired four times, reused three times. Next loading, if there will be one, will be for the fifth use.
Continuing to use and reuse cases, we’re not really using the same cases each time. The cases change, and much of the change comes from material flow, which is brass.
Here’s how it goes, which is to say here’s how it flows: Case neck walls get thicker. The case head area body walls get thinner, over a short span of the body. Primer pockets get shallower and larger diameter. Overall, the alloy hardens over the whole case.
As gone on about a few times in this spot, there’s going to be more change in cases run through a semi-auto than those used in a bolt-action. That’s because of the necessarily additional (comparatively speaking) sizing and also the additional stress resulting from the firing cycle. There’s more flow because the cases are free to expand more.
All case necks expand to whatever the chamber allows. There’s no relationship between that and sized dimension because, clearly, there has to be a small enough neck inside diameter to retain the bullet. It is, though, one of the reasons case necks tend to give up quickest (plus it’s the thinnest-walled area on a case).
The case neck is my primary concern, and the first thing I check. If the walls get too thick it’s possible to cut the space too close between the case neck and the case neck area in the rifle chamber. There might be interference upon bullet release, and that creates excessive pressure, or sure can. All that depends on what the chamber allows for expansion room.
The most simple check is to see if a bullet will freely drop into a fired case neck. If it won’t, stop! Do not reuse that case as-is. A case that won’t pass this no-tool test has excessively thickened.
Somewhere in your notes should be a figure indicating loaded outside case neck diameter, on new brass. This dimension is exclusive of the sized neck diameter, because when the bullet is seated the neck is going to expand to accommodate the bullet. Another check of loaded outside neck diameter will show if there’s been thickening. If an inside neck sizing appliance is used (a sizing button), then that will tell you also, comparing it to what you also recorded for the new case after sizing it. (And it’s a good reason to always run new brass through your sizing die, even if it’s “ready to go” out of the box.)
I hope it’s clear enough why it’s important to “write everything down.” References, standards are big helps.
Direct checks of the neck walls themselves using a suitable tool will show thickening. However! Case necks don’t necessarily thicken the same over the entire height of the case neck cylinder. Remember, the brass is flowing so moves in a direction, and that part of the case has a wave going forward, toward the muzzle. There can and likely will be a tapering from thicker to thinner. Measure at more than one point.
Safety is one thing, and the most important thing, and then the other thing is accuracy. Case neck “tension” needs to be consistent from loading to loading to get reliable accuracy.
Fixing it? An inside case neck reamer is the easiest and most direct means. However! Make double-dang sure you know the numbers and therefore how and at what point to use it! Many are intended for use on fired (not yet resized) necks. Others are a specific dimension that you may or may not be able to specify. Thinning the case neck walls using an outside case neck turner is another direct remedy. A little tedious.
Reamer or turner, though, this job hasn’t finished until the refurbished case has been run through your usual sizing die, and checked again for diameter.
Well, so much for this here and now. Out of room! More next time…