s&w model 25-2

Hello, I'm new the the S&W Forum and I have a Caliber question, I have a Model 25-2 and as far as I know the were all made is 45ACP but my cylinder fits 45 Colt. Is this Possible? 6" Pinned but not recessed Serial Number starts with N520 2-- Cylinder has a number 9 on it and a M with what...