When ever you shoot a shorter round in a chamber such s a 38 special in the 357 mad, 44 special in a 44 mag, 45 colt out of a 454, and a 454 out of a 460 You must make sure you clean the chamber before chambering the longer round you will get a build up of powder and lead/copper where the shorter round stopped. it can cause a rise in chamber pressures. and if you shoot enough shorter rounds in the chamber you can get flame etched ring in the chamber and it will shorten case life of the longer case as well as make it harder to extract. I know this for a fact I had a 357 mag contender barrel that this happened to.