The oversize chamber throats in M 25-3s made them inaccurate with all commercial ammo. Mine measured .458”! The only way I got reasonable groups out of it was to load bullets from my lightest weight .45-70 rifle mould. They were around 340 grains and reloading data was not available for bullets that heavy back then. M 25-5s also had oversize throats for a few years. S & W replaced some M 25-5 cylinders for free. I never heard of them replacing M 25-3 cylinders, but they may have. M 25-5 cylinders are longer.
The M 25-3 was S & W’s first .45 Colt that was made in sufficient quantity for ordinary folks to find them. That is why they sold for over their suggested retail price for a few years, not because we wanted a commerative. Mine had to go back for warranty repair of a problem unrelated to the chamber throats before I fired it. My M-25-3 was my most disappointing S & W.