The Firing Line Forums - View Single Post - Reloader 7/IMR 3031 as volumetric "substitutes" in black powder cartridges?

dahermit · August 3, 2011, 02:19 PM

The modern powder that was made to replace black powder in cartridge arms is not Rx7 or IMR-3031. It is SR-4759. However, it is not a volume for volume replacement for black powder. It is a bulky powder that fills a larger volume of the case than most other powders.
However, if you are shooting cast lead bullets, I have found the all my rifle cast lead bullet shooting, is is Rx7 that proves to be the most accurate powder. However, there was one cartridge that showed a preference for SR-4759...I do not remember if it was .444 Marlin (in a Win 94), or one of the .45-70's.
In any case, I know of no published data the uses Rx7, IMR-3031, or even SR-4759 in .45 Colt cases.

August 3, 2011, 02:19 PM	#9
dahermit Senior Member Join Date: October 28, 2006 Location: South Central Michigan...near Posts: 6,501	The modern powder that was made to replace black powder in cartridge arms is not Rx7 or IMR-3031. It is SR-4759. However, it is not a volume for volume replacement for black powder. It is a bulky powder that fills a larger volume of the case than most other powders. However, if you are shooting cast lead bullets, I have found the all my rifle cast lead bullet shooting, is is Rx7 that proves to be the most accurate powder. However, there was one cartridge that showed a preference for SR-4759...I do not remember if it was .444 Marlin (in a Win 94), or one of the .45-70's. In any case, I know of no published data the uses Rx7, IMR-3031, or even SR-4759 in .45 Colt cases.