i use the Hornady LeverEvoloution ammo in both my 30-30 and 45-70 Marlins. it functions fine thru both of them. the 45-70 has a LOT of power, probably way more than is necessary, at least for deer. the only reason i can think of it not functioning correctly in your 45-70, is if, by some chance, you got some a little on the long side. my reloads (i use both factory and reloads) function fine @ 2.600", but without digging into the safe, i am not sure what the factory loaded ones measure. i would think, since that is the spec Hornady suppies to re-loaders, it would be what the factory loaded ones measure. one thing you could try, is taking a razor blade, and shortening the tip up some, and see if that fixes the feed issue. i think there is .050" worth of plastic tip there to cut off, if not more. if they function at 2.550" oal, then you probably have found your problem.