4227 is a great powder for that application, has a smooth pressure curve. And, if you're burning it hot, can be very clean.
I read that Hank Williams, Jr likes it in his vintage, 1st Gen .45 SSA's. Hank is a noted Colt collector. Now, it probably leaves some residue in that application. His reason was the smooth pressure curve in those old guns.
I like it in my .45 Colt Marlin Cowboy with 24" barrel. I shoot 300 gr. jacketed and cast bullets with a rather warm load. Burns really clean and it's a 'diller killer. Those big slugs will roll a 'diller with authority. They do tend to over penetrate, however...
DF
