Some reloading ops don’t have to be done in a full-blown shop. Here are a few ideas when space, and comfort, are both at a premium. READ MORE
I recently, at his request, took on the task of teaching one son to reload for his AR15. It was in the middle of the winter and my shop/studio area was pretty much closed down for the season. But he persisted, and it was also just the sort of thing I needed to shift gears and give myself a test of what I truly do know that I set out to share with you all each edition. I say that sort of humorously, but not really! Getting back to the basics, starting from the start, is a great idea. I recollect from experiences in what amounted to another life for me (I used to be a PGA Member), the great golf champion Jack Nicklaus would return to his original teacher, Jack Grout, at the start of each PGA Tour season and say: “I’m Jack Nicklaus. I’ve been thinking about taking up golf. Can you show me how to hold the club?”
So the immediate challenge for me was to make this learning experience worthwhile and also comfortable! And easy given the busy schedules we both have.
Many of us have well thought out and lavishly equipped reloading work spaces, and, others, not so much. All during the many many years I’ve been reloading, I’ve lived in apartments, moved to new locations, and, either way, didn’t always have access to the well-lit and sturdily-constructed “loading bench.”
I’ve made do, and, looking back, I don’t think I ever missed a point as a result.
Tricks and Tips
C-clamps are wonderful allies! Mounting many tools doesn’t require direct bench-top fastening. For years, even with a full-scale shop to stretch out in, I have been a fan of mounting tools on “platforms” and then clamping that to the bench when needed. I have a penchant for efficiency in loading and a big part of satisfying that is being able to relocate tools. In other words, I don’t want to have a trimmer, priming tool, and so on and on, all mounted in a (long) row along my benchtop. I want to be able to locate them where I want them, when I need them.
Get to the hardware store and invest in some wood pieces, fastener-fixtures, and hex-head-screws. Take a priming tool, for instance, and mount it to the wood and then clamp that to the benchtop (or any suitable surface, anywhere) and commence to using it. Simple!
I’ve also had good success locating the tool mount spots I prefer for various appliances on my benchtop and then using the hex-head screws to attach the tools via installed threaded fastener receptacles when I want to use them.
I’ve even taken to doing that in mounting big tools. The bench where I load ammo is also the same bench where I build guns, or they share common area. After getting tired of bolting and unbolting vises and presses, I mounted each to a 2X12 piece of wood and affix either to the benchtop using a couple of honking c-clamps. As long as there’s enough area to get a good clamp down and enough surface area to sit the bench, I cannot tell the difference.
Now, when it comes to some higher weight and higher leverage tools, like presses, some of what you can get away with, in a way of looking at it, has a lot to do with how sturdy the base platform needs to be. Sizing .223 Rem.? Not much stress. Bigger cases, more stubborn ops, might need more substantial grounding.
For us, a combination of c-clamps and factory-mounted clamps on some of our meters and presses meant we could set up alongside each other at, believe it or not, our kitchen table and load in comfort, and easy access to a refrigerator!
There are also some handy ready-made bases for loading available HERE at Midsouth.
Point is, if you don’t have access to a conventional bench, work area, or you want to prime cases while you’re watching television with your friends or family, there’s a solution. It just takes a little creativity.
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
Before getting into improving bullet velocity Standard Deviation, it’s first necessary to understand what it is, and what it isn’t. KEEP READING
I got started on this topic last time, and kind of came in through the side door. Quick backstory: the topic was how to start on solving unsuitably high shot-to-shot velocity inconsistencies. This time we’ll start at the other end of this, and that is taking steps to improve already suitable velocity deviation figures.
Clearly, the first step in getting involved in velocity studies is getting the velocities to study. Of course, that means you need a chronograph. Midsouth Shooters has a selection and there’s a direct link in this article.
Virtually all chronographs are going to be accurate. A well-known manufacturer of shooting-industry electronics once told me that unless a chronograph displays a reading that’s just crazy unrealistic, you can rely on the number. The reason is that the current state of circuitry is pretty well understood and heavily shared. Pay attention, though, to setting up the device according to suggestions in the instructions that will accompany the new chronograph. The more recent Doppler-radar-based units are not technically chronographs, but they function as such. The advantages to those are many! More in another article soon. For now, for here, what matters is getting some numbers.
Point of all that was this: You don’t have to spend up for the best to get a good chronograph. One of the price-point differences in chronographs is how much it will help work with the data it gathers. Most of us any more don’t have to do hands-on calculations. Me? All I want is a number. However, there are a good many that will record, calculate, and print.
Terms and Twists Speaking of calculations, the most known and probably most used expressed calculation of collected velocity figures is Standard Deviation. SD suggests or reflects the anticipated consistency of bullet velocities (calculated from some number of recorded velocities). “Standard” reflects on a sort of an average of the rounds tested. I know saying “sort of” disturbs folks like my math-major son so here’s more: SD is the square root of the mean of the squares of the deviations.
Standard Deviation calculations did not originate from ballistic research. It’s from statistical analysis and can be applied to a huge number of topics, like population behavior. SD calculation forms a bell curve, familiar to anyone who ever had to take a dreaded Statistics class. The steeper and narrower the apex of the bell, the narrower the fluctuations were. But there’s always a bell to a bell curve and the greatest deviations from desired standard are reflected in this portion of the plot. Depending on the number of shots that went into the SD calculation, these deviations may be more or less notable than the SD figure suggests.
If you have no electronic gadgetry to help: add up all the recorded velocities and divide them by the number of records to get a “mean.” Then subtract that mean value from each single velocity recorded to get a “deviation” from the mean. Then square each of those. Squaring them eliminates any negative numbers that might result from cancelling out and returning a “0.” Add the squares together and find the mean of the squares by dividing again by the number of numbers — minus 1 (divide by n -1; that eliminates a bias toward a misleadingly small result). Then find the square root of that and that’s the Standard Deviation figure, which is “a” Standard Deviation, by the way, not the Standard Deviation.
Knowing a load’s SD allows us to estimate-anticipate how likely it is for “outliers” to show up as we’re shooting one round after another. Based on the distribution based on the curve, if we have an SD of 12, for instance, then a little better than 2 out of 3 shots will be at or closer to the mean than 12 feet per second (fps). The other shots will deviate farther: about 9 out of 10 will be 19 fps, or less, from the mean. 21 out of 22 will be 24 fps closer to the mean. Those numbers represent about 1.00, 1.65, and 2.00 standard deviations.
Now. All that may have ranged from really boring to somewhat helpful, to, at the least, I hope informative.
Mastery of SD calculation and understanding doesn’t necessarily mean smaller groups. It gives a way to, mostly and above all else, tell us, one, the potential of the ammo to deliver consistent elevation impacts, and, two, reflects on both how well we’re doing our job in assembling the ammo and the suitability of our component combination.
I honestly pay zero attention to SD. I go on two other terms, two other numbers. One is “range,” which is the lowest and highest speeds recorded in a session. The one that really matters to me, though, is “extreme spread.” That, misleading on the front end, is defined as the difference between this shot and the next shot, and then that shot and the next shot, and so on. Why? Because that’s how I shoot tournament rounds! This one, then another, and then another. A low extreme spread means that the accuracy of my judgment of my wind call has some support.
Depending on the number of shots and more, SD can be misleading because it gets a little smaller with greater amounts of input. Extreme spread doesn’t. I have yet to calculate an SD that put its single figure greater than my extreme spread records.
Lemmeesplain: The shot-to-shot routine is to fire a round. It’s either centered or not. If it’s not centered, calculate the amount of correction to get the next one to center. Put that on the sight. Fire again. If I know that there’s no more than 10 fps between those rounds, that’s no enough to account for (technically it can’t be accounted for with a 1/4-MOA sight) then it’s all on me, and if it’s all on me I know that the input I got from the last shot, applied to the next shot, will be telling. Was I right or wrong? It can’t be the ammo, folks. Then I know better whether the correction is true and correct.
Some might be thinking “what’s the difference?” and it’s small, and so are scoring lines.
A load that calculates to a low SD is not automatically going to group small, just because it has a low SD. Champion Benchrest competitors have told me that their best groups don’t always come with a low-SD load. But that does not apply to shooting greater distance! A bullet’s time of flight and speed loss are both so relatively small at 100 yards that any reasonable variation in bullet velocities (even a 20 SD) isn’t going to open a group, not even the miniscule clusters it takes to be competitive in that sport. On downrange, though, it really starts to matter.
For an example from my notes: Sierra 190gr .308 MatchKing, in a .308 Win. Its 2600 fps muzzle velocity becomes 2450 at 100 yards and 1750 at 600 yards (I rounded these numbers).
If we’re working with a horrid 100 fps muzzle velocity change, that means one bullet could lauch at 2550 and the next might hit 2650, in the extreme. The first drifts about 28 inches (let’s make it a constant full-value 10-mph wind again to keep it simple) and the faster one slides 26 inches. That’s not a huge deal. However! Drop — that is THE factor, and here’s where inconsistent velocities really hurt. With that 190, drop amount differences over a 100 fps range are about 3 times as great as drift amounts. This bullet at 2600 muzzle velocity hits 5-6 inches higher or lower for each 50 fps muzzle velocity difference. That is going to cost on target. And it gets way (way) worse at 1000 yards. Velocity-caused errors compound on top of “normal” group dispersion (which would be group size given perfect velocity consistency).
This 100 fps example is completely extreme, but half of that, or even a quarter of that, still blows up a score, or creates a miss on an important target.
That all led to this: What is a tolerable SD?
I say 12. There has been much (a huge amount) of calculation that led to that answer. But that’s what I say is the SD that “doesn’t matter” to accuracy. It’s more than I’ll accept for a tournament load, but for those I’m looking for an extreme spread less than 10 fps (the range might be higher, but now we’re just talking terms). More later…
Shot-to-shot muzzle velocity consistency is almost always a high-ranking goal for the handloader. But what about when it’s just awful? READ MORE
Last edition the topic was a wide-scope look at propellants, and the underlying point was how to get started, how to choose one. There’s not a perfect answer to that, or not one I can warrant as absolutely decisive.
Propellant choice often comes down to experience (good and bad), and that’s one reason that many of us, and me most definitely, tend to stick with a few, and those also are the first we’ll try when starting up with a new project. It’s also one reason we might be hesitant to try a propellant again if it didn’t work well the last time. I have those hesitations.
There are also criteria that we’d all like to have met, and, as also said last time, sometimes those have to be ranked or weighted. We may not find the maximum velocity with the smallest group size with one propellant, and, for me, group size gets the most weight. That’s why I said that the best choice is often the one with the fewest compromises, and that’s assuming there’s likely to be some compromise, somewhere. And that’s a fair and wise assumption.
One criteria that I and others have pretty high on our lists is velocity consistency. One measure of a “good load” is low variations in measured muzzle velocities. This, without a doubt, is of more importance the more distant the target.
The propellant that tested showing the lowest shot-to-shot velocity deviation does not necessarily mean that load combination is going to be the most accurate. One reason it’s important might not only to do with on-target accuracy as it does with providing clues about either the handloading protocols we’re following or the suitability of the component combination we’re using.
This article will focus more on that last — suitability of the component combination — and more to follow later will be dedicated to the performance component of consistent velocities.
I got a letter just before doing this article asking about reasons for seeing high velocity deviations. This fellow, a loyal reader of my books, was using the same component combinations and tooling advice I take myself and also publish, and not getting good results. As a matter of fact, his results were horrid. He was seeing deviations, shot-to-shot, in the vicinity of 100 feet per second (fps), plus. That’s huge.
After much time spent testing all this to collect enough notebook entries to think I have some handle on it, a half grain (0.50 gr.) of propellant in most small- to medium-capacity cases (say from .223 Rem. to .308 Win.) is worth about 40 fps. Given that, 100 fps difference is not likely to come from a propellant charge level variance.
Another reader posted a comment-question last article here regarding how to know if aged components were still good, still performing as they should, and this is a place to start looking if we’re seeing radical inconsistencies.
Two questions at the same time, as I’ve said before, usually point me toward a topic.
Moisture is the enemy in propellant and primer storage. The “cool dry place” is hard to come by, around these parts anyhow. I’ve had propellant go bad after having been stored in resealed containers. So far, I haven’t had any lose its potency after many years of storage in the factory-sealed containers.
“Go bad” can mean at a couple of things, by the way. One is that the propellant ages to the point that it changes. If propellant “spoils” it smells bad! It will have an acrid aroma. Don’t use it. Another way it goes bad is pretty easy to tell: it clumps. That is too much moisture. Don’t use it. Put it out in the garden, it’s a great fertilizer — honest.
Primers? It’s hard to tell… Bad primers still appear good.
My letter-writer’s huge velocity deviations were solved by a change of primer, and, mostly, a box of fresh primers. I kind of knew that was the component-culprit because he was having the same results or effects from different propellants.
Primers should be stored in air-tight containers, which will be something other than the factory packaging. Primers are “sealed” but that’s a lightweight assurance. Touching them, for instance, won’t hurt them, contrary to rumors, but more prolonged exposure to excessive moisture can and will take a toll, and its effects are very likely to be as inconsistent as the performance of the compromised primers.
Another strong caution: Always remove, or never leave, however you prefer, propellant in a meter. After you’re done with the loading for the day, return it to its storage container and cap it back tightly. Same with primers. Any left over in the priming tube or tray should go back to safe storage. Clearly, this all has a lot to do with the environmental conditions of your loading-storage area.
Out of curiosity, I filled a case with some small-grained extruded propellant and left it sit out in my shop. It was clumped when I checked it next day (24 hours). I had to get a pipe cleaner (nearest handy tool) to get it all out of the case. I don’t store propellant or primers in my shop, and that’s the reason… Yes, we have some humidity in my part of the world.
Excluding those obvious issues, what makes some combinations produce higher or lower velocity consistencies takes some experimentation to improve (or give up on).
Sometimes (many times) this all seems more like art than science. It is science, of course, but it’s not tidy; it can’t always, or even often, be forecast.
I’ve seen the biggest effect from a primer brand change. I also, though, don’t swap primer brands around each time I do a load work up and the reason is that there are other attributes I need from a primer. Since I’m loading nearly always for a semi-auto, an AR15 specifically, I have to use a “tough” primer, and that also means one that will accept near-max pressure without incident.
Point is that if you’re running a rifle/ammo combination that isn’t limited by either propellant choice or primer choice, you might very well see some influential improvements by trying a different primer (after getting the propellant decided on). Do, always, reduce the charge at least a half grain before using a different primer brand — primer choices also decidedly influence velocity and pressure levels. Again, in my experience, more than you might imagine.
Next time, more about the performance component of consistent velocities, and a whopping lot more about how to improve that.
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.
It’s not all the same! Depending on needs and application, there are three decisions that can have an impact on your satisfaction. READ MORE
Last time I offered a few ideas on loading the same cartridge for use in different rifles. Essential message in that was, in one word, “compromise.” There’s some give and take when we’re trying to please more than one at time, as such is life…
Choosing cartridge cases is a little, to a lot, the same. Different rifles, different action types, different uses, different budgets, all suggest input that helps determine what works best, all around.
There are three things to consider, maybe four.
One is the action type. Semi-autos need “tougher” brass. That, overall, means “harder,” not necessarily thicker. Due to the resizing requirements for good function, which means a little “more” in all areas, there’s likewise more expansion in each subsequent firing. Brass made of harder alloy is less, not more, susceptible to failures — by my experience. Considering the elastic and plastic properties of brass, harder exhibits a little less effect from each.
I prefer harder composition brass for a bolt-gun too. Most NRA High Power shooters do. Reason? It runs better! There’s less “stickiness” in running the bolt for rapid-fire events.
Two: case capacity. They are not nearly all the same! My experience has shown me that more capacity is better, and that’s especially if we’re wanting to edge toward max-pressure loads. Even though the pressure generated inside the case using more (larger case volume) or less (smaller volume) may get to the same level, there is usually more net velocity (at the same pressure) when there’s more room in the case. If it didn’t matter then other things done to expand case capacity (like shoulder angle changes) wouldn’t matter either.
Three: Precision standards. What do you expect, what are you willing to do to get it? After enough experience with enough different brands, that is a legit question. Some brass is “better” out of the box. Cost usually reflects on initial quality. Paying a premium for premium quality, which is three things: consistency, consistency, and consistency. That consistency will primarily, or at least measurably, be in wall thicknesses. The choice there is to buy it or make it. That choice is a balance between effort, value of time, and proven results.
After using enough different brands with varying levels of costs and claims, I think the most honest thing I can tell you is that you’ll likely end up with the overall “best” brass case you can have shopping in the middle, plus a little, and then getting to work on it. A good commercial “name” brand can be made at least effectively close to the dimensional equivalent of a premium brand, like Norma, but it’s not without effort.
Before spending any time weighing or otherwise sorting cases, do all the prep work you plan beforehand. If any prep involves material removal, even trimming, that influences weight accuracy and, therefore, the viability of segregation by same.
Recommendations? Yes. And no.
About the time you decide there’s some certain way some certain thing is, they up and change it. I avoid making too many lumped-together, generalized statements about particular brands because of that. However! I can tell you that some of the “better” brands of brass also tend not to hold up as well, or won’t if there’s much working load to load (expansion, sizing). I’m thinking here of the better-known European brands, like Norma and Laupua. Those are near about dimensionally flawless out of the box, but they tend to be a little on the thick and soft side. I use Norma in my .22 PPC because the cost is worth it. If I drive from Mississippi to New Mexico to shoot a match, that’s the least of my expense.
This is also the reason that every serious competitive shooter I know says to buy up as much of one lot as you can, if you know it’s good stuff. That’s for all components.
Sometimes brass chooses you!
As said last time on the “Multiple Gun” loads, if you’re mixing brass things like case volume do factor. As also suggested then, the best solution is to pick a load that’s in around the 80- to 90-percent range of max. I mix brass all the time. I shoot quite a lot of factory ammo and, yes, I save each case we can retrieve. I clean them all, size them all, and fill them with a “compromise” load I worked up for can blasting. The need for those excursions is not quarter-minute precision.
If you’re looking to save as much as you reasonably can and still get “good” cases there’s honestly nothing wrong with Lake City. The more recent production 5.56 measures pretty well, and it’s tough, and relatively high-capacity. I sho can’t vouch for any other headstamp on mil-spec ammo beyond “LC.” However! I suggest purchasing it prepped. Avoid “range dump.” A big issue with once-fired is which chamber it was first-fired in. Avoid .308 Win. (7.62 NATO)! You DO NOT want to deal with M60 or Minigun leftovers.