fourarmed,
Thank you for sharing your data. What length barrel does your rifle have?
Alliant achieved almost 1,300 f.p.s. in a 24" barrel, but with a heavier 240 gr. bullet using a mild 2 1/2 Remington pistol primer. The heavier bullet obviously created more resisitance for more complete burning of powder. VERY INTERESTINGLY, the pressure they listed was only 12,100 cup, over 20% below the 14,000 cup SAMMI MAP pressure for the .44-40.
I would be careful using large rifle primers unless you recut the primer pockets deeper so that they are below the case head, otherwise there would be a chance to set off a round(s) in the magazine.
I have also used REL7 with very good success in my '73 Winchester (21" bbl.)but with a heavier 215 gr. bullet (427098). I used 25 grs., a capacity load with 2 1/2 Remington primers (1,180 f.p.s.) and a 155 Federal Magnum Pistol primer (1,226 f.p.s.) with vey good groups in the 1" range @ 50 yards.
I have since located some 240 gr. cowboy RNFP bullets and have them loaded over the Alliant load to try. Just waiting for warmer weather.............
C1PNR, factory .44-40 ballistics in the 1940's-1960's were a 200 gr. bullet at 1,301 f.p.s. Unique is too fast burning to produce this velocity at safe pressures for a '73. 2400, 4227, 4759 and REL7 are the powders of choice for replication of the original '73 smokeless loads.
Sincerely,
w30wcf