I went out to a gravel pit today to shoot some .45-70 rounds. I found that Berry’s 350 RSFP copper-plated bullets do lose accuracy at higher velocity. 19 grains of Unique seems to shoot pretty well, about minute-of-shake. 37 grains of IMR 4227 is much more robust but the groups opens up considerably. If expansion testing works at ~100 yards, it could be used for deer close-in. 41 grains of H4198 was all over the paper, literally. It worked reasonably well in cool weather. I expect something like 40 grains will be the go-to charge for hunting at close range.
I was very disappointed that groups were so poor at such low velocity from a Marlin 1895 with 22 inch barrel. I guess I will spring for some 300 JHP for serious deer-hunting at high velocity. Yes, recoil may be the limiting factor. I was wincing quite a bit today. It hurt, and I only fired about 13 rounds. This is not a target-shooter’s rig.
One other bit of knowledge is how to load the magazine through the gate. I kept finding the rounds hanging up or having difficulty getting the gate to close. I settled on a technique of loading from a seated position with the rifle across my lap. Then I had two fingers free, one to push the round in and the other to press down on the round on top of the gate. It worked very well and smoothly. I guess my fingers are a bit to weak to do it with one hand. The gate has a very strong spring.