I use 4.1 grains under a Zero or Montana Gold 230 fmjrn and it make power factor of 170 in my 5 inch 45acp for shooting USPSA matches. Load out to 1.250, Crimp to .472, runs great.
Ive seen two match grade barrels split with clays the cases were double charged with clays powder, way over pressure. Frankly clays scares the sh** out of me. Just my two cents.
I've shot thousands of rounds of Clays loaded 4.0 under a 230 both jacketed and plated. It has been a great load. Sure, you can get a double charge, but I can also double charge a lot of other powders I've run in my .45. You just have to pay attention to what you are doing.