My second centerfire rifle about 45 years ago was a Ruger No 3 in 45-70. Since then I have owned about a dozen 45-70's. I got one of the first Farmer Sharps and shot it in shuetzen matches and later on bought a heavy barrel Shiloh and started shooting 500 grain bullet. Health problems prevent me from shooting except off a bench and my range is limited to 200 yrds. I got out a Mod 63 some time ago and remembered why I really don't want to shoot heavy bullets much with a light sharps or my H&R officer's model. I read my old reloader's manuals and noticed that a 350 grain bullet often shoots well in the 45-70, even though the twist is for heavier bullets. I also remembered that I still have a 385 lyman mold and a Hoch mold I had made for paperpatched bullets which shot very well in the big Shiloh--less than 1" at 100 yrds with iron sights and black powder. My 360 gr NOE mold just arrived and it looks great. Tomorrow I plan to cast a hundred or so bullets out of 40-1 allow. My load worked out years ago was 5 gr 4750 under 62 grns FFg. I use 5744 now that my supply of the 4750 is used up.
Why a duplex load? I got started with duplex loads years ago. Despite all the dire warnings, particularly on the Shiloh forum, I have found duplex loads safe, when done as Ned Roberts recommended and equal in accuracy at 200 yards as straight black, I can shoot all day without having to clean, and more importantly, bullets designed for smokeless often have lube grooves too small to carry enough lube for pure black loads. I use Starline cases, Fed LR Magnum primers, and .20" of compression. I don't have to resize cases for either of the 45-70 rifles I have now. Just slight bell, compression die, and taper crimp. I love NOE molds and the sizing tools they make. I hope the recoil with this load and a 350 gr bullet will be pleasant enough for my metal gong range.