Sometimes the SAAMI specs aren't the only consideration. I was the one who posted the older thread teckhardt mentioned and I ended up with both a 45 Redhawk cut for clips and a 454 Alaskan. I hadn't considered a few things before I actually picked up the 454, throats are huge at .455 and the groove is .453. Add that into the long chamber and you'd need to run at least .454 bullets to expect any decent accuracy which would likely bulge quite a bit in ACP brass. I might still have the gun cut for moons but it would see far more Casull than ACP, I just like moonclips.Interesting. Thought .45 lc and .45 acp used the same diameter bullet?