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.
CHECK OUT CHOICES AT MIDSOUTH
The preceding is a specially-adapted excerpt from Glen’s book Top-Grade Ammo. Available HERE at Midsouth Shooters Supply. Visit ZedikerPublishing.com for more information on the book itself, and also free article downloads.
14 thoughts on “RELOADERS CORNER: Picking Propellants”
I’ve had really good luck with Varget in .223, .243, and .308 in rifle matches. never mattered what the temperature was.
“Response to the Use = Results”
Which toothpaste do you use?
For my loads the input of weather, altitude and target are the first considerations next is the method and component choices for reloading followed by response. The equation finalized the use of H10, Varget, VihtaVuori N540 and H4350. There are is occasional use of other powders depending on environmental change. The recipes are for .308, 223, 5.56, .300AAC and 6.5 G&C. Hope you find your recipe … SeaLeopard
Typo … it is H110
It is no easy task in some rifles to find the right propellant. I worked with 2 old-but-good-condition” sporterized Enfields, one dedicated to cast bullets, and the other to higher velocity jacketed rounds. Gave up several times and resolving sheet of paper accuracy with every bullet and powder combination I could imagine. One day I realized that I had never tried old BLC-2. I couldn’t believe it…with both rifles, I started pulling 1 moa groups at 200 yards (2″). I was ecstatic that I had stumbled upon the magic recipes for those rifles. Never give up…”the truth is out there”…somewhere…on the powder shelf in this case.
Any serious issues with using old powder? Or using rounds loaded many years ago? (10, 20, 30 years old)
Great information. It still comes down to testing and what level of performance are you looking for. Sometimes it comes down to what you can find…..
Had a old Mauser, chambered 30-40 Krag years ago that with every bullet wt. & powder & primer I tried shot the same L shaped group. 3 inches tall by 2 inches wide. Cases were RP as that was all I could get back then., Thing was I killed every thing I ever shot at with that old rifle, but 1 buck @ 100 yards. Have no idea where that bullet went. Every shot from 8 yards to 365 yards was a 1 shot kill. On paper it wasn’t that accurate but it worked!
iI was hoping that you guys would at least touch on pistol loading powders. alas , nothing was said. bummer.
Pistol powders have the same qualities and drawbacks. What you choose should be based on your testing and manufacturing data. I use Tight Group for my 9 practice rounds and have found Ramshot S to produce good groups. Both burn clean IMO. Even the type of powder drop will effect performance. I use a Dillion progressive for my handguns and it will not meter large spherical powders consistently.
I know… Reloaders Corner is pretty much a “rifle” department. I think maybe I should start working more with handgun loading. Feedback on that idea would be appreciated!
What did you mean by when you said that you called Hodgdon and they helped you to “sort benchmark out”. Did you decide not to use Benchmark for you 223?
I had seen a pretty wide range of loads published as “good” using that propellant. Some were over a grain more than what Hodgdon listed as max in its data. Needed some insight… Still not clear on the reasons. But, yes, we’re using Benchmark currently with 55 grain range bullets. Very clean! I like it a lot so far.
I saw a question up there about loads that are 20-40 years old, and/or powders & primers that are old. Sealed & in they’re original containers. Can anyone give any answers? I have a lot of powder, primers, and cartridges that have been packed away for decades. Can I find any answers with reasons why or why not? thanks.
I wish I could tell you exactly what the shelf life of components is. Storage matters, of course. Dry matters most. I’ve opened sealed canisters that were 15 years old and no issues. I have had it go bad in a resealed container. If propellant is bad it smells bad! Very acrid. I’m more concerned with primers because unless an alternative means is used, they’re not in air tight containers.