Good questions and interesting read here about the different 4831 powders.
I don’t know about all the folks who claim not to be Murphy but they have very good comments about this old propellant and loading for the 7mm Remington.
Hodgdon 4831 was the first surplus powder marketed, with this label, after WW II and then came the Improved Military Powder 4831. Supplies of the old surplus have long ago dried up and all of it is newly manufactured today, whether IMR, Hodgdon or Accurate 3100. I am sure that the Accurate 3100 and IMR 4831 are one and the same. They come from the same vat or at least the same recipe. They are different from the H4831 of old (surplus) or more recent versions and certainly different from the new H4831sc-Extreme marketed by Hodgdon’ I don’t think the recipe for IMR has changed over the years but I have seen significant variations in it over the years from lot to lot. So much variation in fact, that I shied away from using it for some time. The new H4831sc is made in Australia for Hodgdon and it is a very different powder from the original and different even from the previous H4831 (long cut). Obviously, in the physical kernel size but also in deterrent coating and burning rate. It is far superior to any and all ever marketed under the 4831 label and gives the highest velocity, with the lowest pressure of any I have used. It is temperature stable and very clean burning. It is also the most uniform from lot to lot of any 4831. I use this propellant and its sister powder H4350 extensively and hope these recipes don’t change.
Loading data with these powders or any other powder will vary from lab to lab and loader to loader, myself included. Some of this variation are from the normal lot to lot variations of the powder, some are from the instruments measuring the velocity and pressure and some are from the dimensional differences in the equipment used. These dimensional differences will exist in the rifles we use, also. I have on several occasions fired two, three or more rifles side by side with exact duplicate loads from equal barrel lengths and measured large variations in instrumental velocities. These variations can be as much as 200 fps or more. A very recent example was with H4350 and three different 30-06 rifles all with 24” barrels firing 180 grain Norma Vulcan bullets. None of these loads showed any high pressure signs.
H4350-56.0 grs., Fed. 210M primer, Velocity
Rifle No. 1: Mauser M98, 2743 fps
Rifle No. 2: Remington M700, 2649 fps
Rifle No. 3: Dakota M97, 2816 fps
I once loaded from one 8 pound keg of IMR 4831, for my 7mm Remington, a load of 64 grains and a 160 grain Nosler Partition. This was the load for this rifle. The highest velocity, the best accuracy and made it the envy of many of my hunting buddy’s. Then I ran out of that old bucket of powder. It took about two or three years as this powder was only used for this 7mm and my 6.5-06. I bought a new one pound can hoping to duplicate my old load. It never happened. I hit the limit with pressure long before I achieved the previous velocity with the 7mm and used it up trying, never getting to try it with the 6.5-06. This was back in the late eighties and I have tried various IMR 4831’s since then and have never found my old load. Several years later I bought a Sako 7mm from a fellow who claimed wonderful things from this old rifle with a recipe of 64.0 grains of IMR 4831 and a 160-grain Partition. (Yeah, right.) So I tried once again. I bought three pounds in different lots and tried with the very best of my hand loading talents to bring new life to my old and new 7mm magnum rifles. Didn’t happen. That’s the way it goes sometimes. The frustration of this tedious research can get a fellow down. Why can’t powders work the way they should?
In general, propellant powders are now better than ever. We have more very good powders to choose from than ever before. It seems to me that I get better velocity and lower pressure than ever before. The powders are certainly more uniform in burning rate from lot to lot and cooler burning. We also have the new high-energy powders which, in some cases can add velocity and breathe new life into old calibers.
When we load for a particular caliber, we work up our load with the bullet of choice and get everything just right. We know which one works the best now we’re ready to load for that hunting trip with our best efforts and all of our research and load development about to pay off. Then……we find we’re out of our favorite powder! All we can do is buy a pound and hope for the best, but we still have to start low and work up to it. Don’t just jump in where your last load was and make up 50 rounds, pulling bullets is no fun. I would recommend you always make a note in your log of the lot number of the particular powder and if it is a good batch for you and your rifle, buy a bunch of it if that’s the load you want to use. That’s why they make 8 pound jugs of it. I find a supplier that has 8 pound and 1 pound canisters of the same lot, buy one pound and try it then buy the keg if it works. I always buy at least two pounds of any powder and make sure they are the same lot. Typically, in big rifle, you’ll get about a hundred rounds to the pound.
I shoot up more powder than most hand loaders plus I also load for several others, so I buy a lot of powder. For large capacity rifle cases (60 grains or more) I use H4350, H4831sc, RL-19, RL-22, RL-25 and N560. These cover any application I might have and I keep a good supply. I have a few other favorites also for the smaller cases or bigger bore size H4895 and RL-15 are top performers. I try about all of the newer powders, especially for the huge cases, but haven’t found anything any better than what I listed. I don’t use ball powder, any ball powder, in rifle cases. I find I can do what needs done with my stock and they are always cleaner and more consistent.
When making the perfect load, most accurate, consistent, and at true performance velocity, accuracy is the most elusive. When dealing with large cases, by that I mean 30-06 size and larger, the particular brand, or charge weight, makes little difference. I find if I can achieve the “sweet spot” velocity for the bullet and barrel, we have the best accuracy. There are exceptions, of course, but when dealing with hunting bullets at hunting velocity, and by that I don’t mean maximum velocity, necessarily, the powder used to achieve the ballistics doesn’t matter much. Consistent ignition, that as much a fault of powder as primer to give low standard deviation in velocity, is an important concern, but once we have what works for that bullet/barrel/velocity combo, it can be done with many different powders. Now, some powders won’t ever achieve that velocity without excess pressure, and some will. We only use those that will. If a powder has too fast a burning rate, high pressure will stop us before we reach our “magical” velocity. If the burning rate is too slow, we’ll run out of room in the case before we find our velocity. It is the management of the delicate balance between pressure and velocity that makes this a challenging and rewarding pursuit. There are at least a half dozen powders that are “perfect” for the 30-06 case and 180 grain bullets. And much the same could be said for almost any caliber that could be called a hunting rifle. Finding the right combination, that’s what it’s all about. More shootin’ and more loadin’.