The .32 Colt, short and long, will not quite interchange with the .32 S&W cartridges. The Colt rounds were originally designed to use an outside lubricated, heel type bullet with the case diameter the same as the bullet diameter. The rim diameter and cartridge length are very nearly the same for the Colt and S&W rounds, the only difference is in the case body. A gunsmith could very easily run a .32 S&W long reamer into the chamber and your rifle could then use readily available ammo. That is assuming it is a centerfire, there were also rimfire versions of the .32 Colt.