I have a 5 inch, fixed sight in SS. I bought it just because of the looks, mostly, with an intention to shoot B P when I could get a "round tuit". Those "Tuits being difficult to find sometime, I became aware of the selection of conversion cylinders. I have since bought and used the Kirst in both .45 Colt and in .45 ACP.... Shoots great,perfect fit,very happy with my set-up......Slow, certainly slower than Josey could switch his cylinders, on horseback,at full gallop,but something about the single action has always been enjoyable to handle. I use cowboy loads for the .45 and just any factory loads for the ACP .45.