You should be, at the least, able to get promising groups with R-7 in your 45-70. In fact, it should give at least one really good group. It would be helpful to know the powder charges you have tried and which bullet(s) you have tried as well. I am working with cast bullets in my 45-70, and different powders, but R-7, 3031 or 4198 should give you something that is more than satisfactory. All 3 will duplicate factory velocities. Not criticizing your shooting or shooting techniques, but the Handis are notorious for needing to be held/rested behind the forearm screw, be sure not to over tighten that screw, and 45-70 recoil can be punishing, be sure to not shoot more at a sitting than you re comfortable with. 30 rounds of bullets weighing 330-405 grains at 1300-1400 fps is about my personal limit. After that I begin to lose my concentration. I won't bench shoot 1800 fps 300 grainers at all.