Half-cocked
Senior Meatbag
- Mar 14, 2006
- 23,937
I loaded some 8x56R cartridges the other week; yesterday I finally got up to Hap Baker to test them. These were just a couple of short runs of two different powder types, to get a rough idea of usable (safe) load ranges.
The test rifle was an Austrian M95 Steyr-Mannlicher in very good condition with strong rifling and a shiny bore. "Very Good" for these rifles means anything that the wood hasn't gone totally rotten on. So it looks a little beat up even though mechanically it's in great shape.
The loads that I made up used new Graf's (Prvi Partisan) 8x56R brass, CCI #200 large rifle primers, and Hornady .330" 205 grain spire point bullets. I have seen these also referred to as .329" bullets; they mic out to .3295", anyway. COL for all cartridges was 2.995", +/- .006", with a light crimp on the canellure, using Lee dies.
I used two powders; Hodgdon H4350 and IMR 4895. I started with minimum loads, 41 grains of H4350 (I had previously tested 40 grains of H4350, which were underpowered and had blow-by problems), and 35 grains of IMR 4895. I went up from there in 1-grain increments, up to a couple of grains higher than the max. loads I had seen posted by other reloaders. I intended to stop long before reaching those high-end loads, if there were any signs of excessive pressure.
So, for H4350 I loaded 13 cartridges, in the range of 41-53 grains. For IMR4895, I loaded 12 cartridges, ranging from 35 to 46 grains. 25 cartridges, altogether.
After shooting some nazi milsurp M30 the other week, I can say that maybe only the two highest loads of IMR4895 even approached the milsurp stuff, in terms of noise and recoil.
Temps during the test were around 60 degrees.
I ran through the H4350 first; the first few rounds had very mild recoil. Every primer looked fine, afterwards, and recoil didn't really feel very stout until the 44 grain charge. The last couple, 52 and 53 grains, were a little over the highest load I've seen reported anywhere else, but even so the recoil was less than milsurp, and the cases and primers looked perfect afterwards.
The second batch was the IMR4895. Again, recoil at the start was very light. I inspected every cartridge and primer carefully after every shot; there were no signs of overpressure that I could see. Only until the last shot, 46 grains of IMR4895, did recoil seem anything like with the milsurp ammo, but again the primer and cartridge looked perfect afterwards; no cratering or excessive flattening, no stretching or splits. I think there is still upward room for testing with both powders.
I need to get a chronometer, before I do any more testing... I would love to see if I'm getting anywhere near the FPS of the milsurp ammo. It would be nice to find out if I can duplicate the milsurp MV but with a milder recoil, using modern powders. The Hornady soft-point 205 grain bullets would make the M95 an awesome brush gun.
I've attached a scan of the test cartridge's bases, for reference.
The test rifle was an Austrian M95 Steyr-Mannlicher in very good condition with strong rifling and a shiny bore. "Very Good" for these rifles means anything that the wood hasn't gone totally rotten on. So it looks a little beat up even though mechanically it's in great shape.
The loads that I made up used new Graf's (Prvi Partisan) 8x56R brass, CCI #200 large rifle primers, and Hornady .330" 205 grain spire point bullets. I have seen these also referred to as .329" bullets; they mic out to .3295", anyway. COL for all cartridges was 2.995", +/- .006", with a light crimp on the canellure, using Lee dies.
I used two powders; Hodgdon H4350 and IMR 4895. I started with minimum loads, 41 grains of H4350 (I had previously tested 40 grains of H4350, which were underpowered and had blow-by problems), and 35 grains of IMR 4895. I went up from there in 1-grain increments, up to a couple of grains higher than the max. loads I had seen posted by other reloaders. I intended to stop long before reaching those high-end loads, if there were any signs of excessive pressure.
So, for H4350 I loaded 13 cartridges, in the range of 41-53 grains. For IMR4895, I loaded 12 cartridges, ranging from 35 to 46 grains. 25 cartridges, altogether.
After shooting some nazi milsurp M30 the other week, I can say that maybe only the two highest loads of IMR4895 even approached the milsurp stuff, in terms of noise and recoil.
Temps during the test were around 60 degrees.
I ran through the H4350 first; the first few rounds had very mild recoil. Every primer looked fine, afterwards, and recoil didn't really feel very stout until the 44 grain charge. The last couple, 52 and 53 grains, were a little over the highest load I've seen reported anywhere else, but even so the recoil was less than milsurp, and the cases and primers looked perfect afterwards.
The second batch was the IMR4895. Again, recoil at the start was very light. I inspected every cartridge and primer carefully after every shot; there were no signs of overpressure that I could see. Only until the last shot, 46 grains of IMR4895, did recoil seem anything like with the milsurp ammo, but again the primer and cartridge looked perfect afterwards; no cratering or excessive flattening, no stretching or splits. I think there is still upward room for testing with both powders.
I need to get a chronometer, before I do any more testing... I would love to see if I'm getting anywhere near the FPS of the milsurp ammo. It would be nice to find out if I can duplicate the milsurp MV but with a milder recoil, using modern powders. The Hornady soft-point 205 grain bullets would make the M95 an awesome brush gun.
I've attached a scan of the test cartridge's bases, for reference.
I think we share enthusiasm for the M95. It's an unusual, different and very interesting carbine. It's a really nice shooter - (Ya'll w/ C&R's...good ones aren't too expensive! Hint, hint). Reality is, unless you load for it, price of ammo sucks.
Still seems light, but I'm working it up.
