I've put over 1700 BP and 200 grain big lube bullet rounds through my 44-40 '66 carbine so far this year. I haven't torn it down yet, and it's still running smoothly. Only maintenance has been to clean the bore and chamber after a match.
On a similar note, I have a 44-40 Henry that I shot for three years before I took the side plates off. It wasn't really necessary.
Fingers (Show Me MO smoke) McGee - AKA Man of Many Colts - Alter ego of Diabolical Ken; SASS Regulator 28564-L-TG; Rangemaster and stage writer extraordinaire; Frontiersman, Pistoleer, NRA Endowment Life, NMLRA, SAF, CCRKBA, STORM 327, SV115; Charter member, Central Ozarks Western Shooters
Cynic: A blackguard whose faulty vision see things as they are, not as they should be. Ambrose Bierce