Author: britrifles
Subject: Flight of the Bumble Bee
Posted: September 29 2020 at 8:39pm
IMR 3031 is quite versatile, and also quite an old powder. Many published loads because it’s been around for so long. It’s one of the faster burning rifle powders in the “medium” burn range, so might be counterintuitive to use with a heavy bullets. It meters like gravel thru my powder measure, a relatively long grain extrusion.
Subject: Flight of the Bumble Bee
Posted: September 29 2020 at 8:39pm
IMR 3031 is quite versatile, and also quite an old powder. Many published loads because it’s been around for so long. It’s one of the faster burning rifle powders in the “medium” burn range, so might be counterintuitive to use with a heavy bullets. It meters like gravel thru my powder measure, a relatively long grain extrusion.
1970 Lyman Reloading Manual, max charge and velocity with a 215 Jacketed bullet:
IMR 3031 36.0 gr. 2057 fps
IMR 4064 39.0 gr. 1996 fps
IMR 4895 40.0 gr. 2217 fps
IMR 4320 41.0 gr. 2217 fps
The above loads appear to be quite conservative compared to what is in the 1960 NRA Reloading manual for 215 gr and 216 gr bullets (instrumental velocity 20 feet from muzzle):
IMR 4320 43.5 gr. 2360 fps 44,300 CUP
IMR 4350 49.5 gr. 2432 fps 44,630 CUP
Note the NRA manual loads were tested in a British Government 5 groove pressure barrel described as 26 inch long, .3146” groove diameter, .303” bore.
All above loads with standard large rifle primers. Commercial cases.