SR 80 Smokeless Powder Transition Years

Post 1913 Sporting Powder Rifle No. 80

.....continued from Dupont No.2

In 1913, DuPont introduced SR80 (Sporting Rifle) . It was a granular type powder, similar in appearance to DuPont No.2 Bulk Smokeless but was a bit faster burning and was not a "bulk" type powder. It's burning rate was in the same range as "Sharpshooter".

“Sharpshooter” and "SR80" fueled millions of .44-40 smokeless factory cartridges up until at least the 1950’s (SR80 was discontinued in 1939) when ball powders began appearing on the scene. Winchester switched to a ball powder similar to the old W630 which also has a similar burning rate to 2400. Remington continued to use “Sharpshooter”.

During all that time,factory ballistics for the standard cartridge remained at 1,300 f.p.s. with a 200 gr. jacketed bullet.

I have had the opportunity to find and shoot cartridges of the period and they equaled and sometimes slightly exceeded the 1,300 f.p.s. cataloged velocity.

By the early 1970’s, factory ballistics had been reduced to 1,190 f.p.s. in the catalogs. The reason? Faster burning powders in smaller 7 to 8 gr doses had replaced the slower burning powders. Thus, to keep the pressures within the specified limits for the .44-40, the velocity was reduced.

Unlike the earlier smokeless cartridges that produced catalog ballistics, I found that in testing the current Winchester and Remington JSP cartridges, they fell a bit short of the 1,190 f.p.s.specification ( closer to 1,150 f.p.s. average).

By the 1990’s a new class of.44-40 cartridges were introduced called “Cowboy”. This was due to the interest in Cowboy Action Shooting. Bullets were lead or lead alloy going at around 900-1000 f.p.s.(rifle). Ballistics are 30+% reduced from the original smokeless (and black powder) cartridge and are just fine for recreational shooting.

w30wcf