The strongest opentop you'll probably find is the Cimarron 1872. This is stronger than any "conversion" because the center pin has a deeper thread than the conversion, which has less thread than the percussion because of the conversion plate. I have an 1872 in 44 Special, it also comes in 44 Russian, 44 Colt or 38 Special. The wedge is harder than a file on these, as opposed to the prcussion wedge which is soft. It is a solid wedge, no spring, and has a screw with a flat on it for release of the wedge. I fire reloads with 200 gr bullets, 6 gr Unique or 5 gr Titegroup.