Hey Gus, usually what I do is ask them to make it to fit the frame of a Ruger Vaquero. They are just a tad bigger. A Colt will slide farther down into the holster and not hurt it. While, if, if.... you should ever change guns, a Vaquero will fit in quite nicely instead of being forced in. Just my 2 cents on how I order my gun leather. Never know when you might decide to shoot something different and the gun leather will fit either.