Numbers (names) of powder

[ants]

When I peruse the shelves and look to my wallet for the list, I find it sweat soaked and illegible.

This is me, I'm still chuckling about it. Me and my little lists.
Not just gunpowder on the shelf, but everything from Auto parts to Zinc fittings.
I make my little list, and either leave it at home or ruin it in my own pocket.

 

[jrmartin1964]

I think that I heard this one on this site. When .303 British cartridges used cordite powder, they corroded the rifle barrel. So the US developed 303-1 powder that was non-cordite, and did not have the corrosive effect. So IMR 3031 was developed after or during WWI.

IMR-3031 was developed by DuPont. It was first produced in 1934, and was released onto the commercial market in mid-1935. It was developed as a modification of (and improvement upon) the earlier IMR-17 1/2 (introduced 1923, discontinued 1934), itself a modification (added tin content) of the even earlier IMR-16 (introduced 1916, discontinued 1927). The powder developed for .303 British was IMR-17 (introduced 1917, discontinued 1925), which was also a minor variation of IMR-16, and had nothing specifically to do with the development of IMR-3031.

This information comes from "Complete Guide to Handloading" by Philip B. Sharp (1937 edition)

 

[jrmartin1964]

FWIW, DuPont's 4-digit IMR powders were numbered in the order of their development. IMR-3031 was, quite literally, the 3031st smokeless powder formulation of the Improfed Military Rifle powder series developed by DuPont. Likewise for the others: 1204 and 1185 (both now long obsolete), 4064, 4198, 4227, 4320, 4350, 4831, etc., which means there were hundreds of powder formulations that either never made it past the development stage or were simply never released in canister lots. Hodgdon's H4831 (actually produced by DuPont) was the non-canister grade IMR-4831 used during WWII to load shells for the 40mm M1936 Bofors aniti-aircraft gun. At the end of WWII, with the need for 40mm AA shells gone, the U.S. government released tons of surplus 4831 for sale. Hodgdon saw an opportunity, bought the stuff by the railcar load. As it was not "canister grade" (or, consistent from lot-to-lot), loading data had to be carefully worked up for each lot. DuPont soon realized there was a market for a canister-grade, and started producing consistent lots of the old IMR-4831 for commercial consumption.

And the rest - as they say - is history.