IMR-3031 for a priming charge? Hmmm...never occurred to me to try it. I've always use SR-4759 I guess because that's what almost everyone else used. I've had good results with it but have never worked very much with a 45 cal. case longer than the 2.6 in a Ballard. That extra length has to make a difference.

I know of several fella's who use 5744 in quite a few old straight walled cartridges but I don't believe any are as big as the 50-70. I want to remember most are in the 38-55/9.3 X 72R class cases. According to them their results are pretty good. I tried it in a Schuetzen rifle chambered to a cartridge based on the 8.15 X 46R with the neck and shoulder completely blown out to a straight taper and of .345 groove diameter and it didn't work nearly so well as IMR-4227. Come to think of it that rifle didn't like a straight load of SR-4759 either. Re-7 worked quite well.

I've both read and heard of Trail Boss getting a little goofy pressure-wise. It works well in the few cartridges I use it in, one being a Ruger #1 in 450/400 under cast bullets so "no worries" there. And doggone it, with a 413 gr. bullet cast of 50/50 lead/lino it is very accurate!!! Truth is that particular load with that bullet equals my 40-70 Shiloh Sharps so it's nothing new for me, except that it's smokeless.

Welp, time to get ready for church!!