H, IMR or RG? Or all of the above?
Oh all of the above. They're all fine for carefully gassing my M1As. There was a great article some years ago, maybe twenty years ago or so or longer on the old UseNet, about handloading for the M1a and it was so comprehensive ... it covered all the 4895s including the recipe the Portuguese and Spanish were using (I forget the title designator they used) but in that general weight, the 147-155 weight class of projectiles, some used-to argue that the 4895s were ideal in x51 ... although, of course, it was the original military ball (as in 7.62 fmj, not ball powder) 30-06 propellant of choice.
Bruce Hogdon's first powder, if the story serves me correctly that I read some years ago in a Handloaders Digest (I'll try to find that later today) .... his first powder, H4895, was a knockoff of the military government exteuded 4895 that he was selling as surplus powder when he opened his business. That was the old Dupont version which I used to use, which later became extreme extruded IMR 4895 and so on. The 16 pounds of Radway Green I'm going-through now, military surplus, is the NATO version of course and was the last of the surplus 4895 that came out of their old Radway Green facility in England which is where I suspect those old tungsten AP rounds were pulled that the OP shared with us. Or they may have been pulled here somewhere as millions of those rounds were demilled in the 90s both here and there. Those were loaded in x51, using this Radway Green RG 4895 that I have, in the 70s, probably late 70s or so before that plant was shut down and retooled.
I cannot remember whether I picked up all of this RG 4895 from Jamin when he was selling surplus powder and bullets out of his house (before he started PSA) or whether I bought it at Widener's back in the day while I was up at our mountain home in Johnson City ... I think it was Widener's and I paid maybe $40 bucks a keg for it. I had four 8 pd kegs and I'm down to two now ... been trying to work-up a 45-70 load using some of it because I know this powder has to be pushing 40-50 years old but it's still going strong.
Anyways, I've used so much RG 4895 and those old pulled AP pills ... back in the day we would go to the back forty in this old abandoned junkyard and shoot engine blocks with the stuff before they sold all those junkers for scrap to China. LOL, I always wondered what some China scrap dealer would think when he saw those blocks full of what were obviously bullet holes . (Engines were always pulled before the shells were crushed - stripped and drained engines went out whole, by rail, to the west coast).
Those Chinamen probably imagined some hollywood gangsta street war taking place and the engines being shot full of holes. What they failed to realize, I can almost guarantee, is that it was simply good old Southern Boys exercising our 2A rights in a massive remote country junkyard full of yotes, feral dogs and rattle snakes ... all of them using the old cars and trucks as breeding dens.
I'd love to get my hands on some more of those projectiles. Wish I had held onto some of them back then. Like those old green box tuna-can Norinco steel penetrators from China in x39 .... good gosh they were a nickle a piece back in the day, loaded, steel cased!
Who could have ever imagined things would be where we are today.
But yeah Geo ... this RG 4895 is perfect for those. All we used to do was basically reassemble them inside our own FC surplus brass we were getting from Top Brass with #34s already seated.
Amazing times ... hindsight is so 20-20.
I have a couple of M1As that love to eat those things.
