For factory level performance I haven't found a Marlin yet (out of 5 so far) that wouldn't shoot the Remington 405 grain load MOA or better. Unless you're plinking a lot, it doesn't make a lot of sense to handload for that level of performance IMHO.
For handloads, I worked up 2. Both use WW brass and Federal 210 match primers. One was 47 grains of IMR 3031 and a 405 grain RCBS GC bullet .. actually 425 cast from wheel weights with a GC and lube. It was about a 1.5 MOA load. The other was 52 grains of H4895 and the 400 grain Speer bullet. It was repeatably 0.7 MOA or better. (All groups were shot w/ a scope. Scopes varied from 1.5-5X to 3-9X Leupolds, favorite was a 1.75-6X.)
Much as i like .45-70, some where between selling my guide gun back about 2008 ... ish ... and buying the 2nd Marlin Cowboy rifle about 3 years ago, I lost my love for having the hell hammered out of me. It wasn't so much the shoulder as it was the headaches I was getting from recoil. I'm probably out of the .45-70 biz unless I go heavy, like Sharps heavy. Wish Marlin would bring back the cowboy .38-55.
Tom
