On my prior "false alarm" posting (oops!) about the availability of IMR sr4759 powder, a fellow shooter suggested that I try Accurate Arms xmp5744.

Well, I've done that, and as you can see from the attached pictures, so far the SR4759 burns much cleaner for me. Both of these pix were taken after firing 10 rounds:

AA xmp5744:
Hunt101

IMR sr4759:
Hunt101

The unburned powder in the 5744 loading was enough to drop a couple grains down into the action and prevent the hammer on my Winchester High Wall from staying cocked when cycling the lever -- not good!

Has anyone else experienced this with this powder, or does it suggest I might need to increase the charge weight of the 5744???

I like the sr4759, but it's always good (and fun!) to test other options.

Old No7

7,

I have a couple of old single shots used for Scheutzen in 38-55. My load was about 15 grs of IMR SR 4759 and a small tuft of kapox with a 250 gr cast bullet.

Good effort on the pics. Do you think the pressures are similar?

I agree that the 4759 load burns cleaner. But the significant question should be "how does that xpm 5744 load group??



When you said "black powder substitutes", I assumed you meant stuff like Pyrodex, rather than "smokeless substitutes for black powder" in a BP cartridge rifle. I think the AA stuff will burn cleaner in larger charges and higher pressures. But if you are willing to go the kapok or dacron wad route, you might try Alliant 2400 or even Unique in small doses. Lyman MUST have published some cast bullet .38/55 loads in years past using such propellants!