On a whim sent in and got a 450 Marlin barrel just to try the Hornady Leverevolution ammo at full strength. I haven't had the problem you have had Stimpy. The Hornady ammo shoots about 2 1/2 inch groups at 100 yards and think part of that is recoil anticipation. Man those things hurt even with the stock loaded with lead and an extra shotgun slip on pad. I can only handle about 5 shots at one sitting. Took two trips to the range just to sight it in properly. However, the same hunting load I use for my 45/70, 52.1 grains of RL7 and a 300 gr HP with CCI 200 primer, is just as accurate as in the 45/70 and about 3 inches lower than the Leverevolution ammo so sighted the handloads dead center and left the store bought 3 inches high at 100. Now if I ever have a reason to carry it for a 200 yard shot I'm ready.
Have to agree. For a normal, non-Handiholic person, a 45/70 is all anyone would ever need in this caliber.