I have a Joseph Lang Jones underlever, non-rebounding hammer gun which is somewhat slow to reload but once you get used to the "dance" of half-cock then open it's fine for shooting where a fast reload isn't needed. It does fine on clays and is my favorite quail gun. As far as the strength of lockup I don't know because I've only put 6,000 rounds through this gun which was completed March 6, 1866 and it's as tight as the day I bought it.