255 Keith is the gold standard of versatility for the 45 Colt, IMHO. It's capable of shooting tighter than I can hold and anchoring anything I'm likely to.....aggravate.
Since I cast I can tweak the alloy to suit my needs. Gas checks not necessary for the loads I like but if I wanted my RBH to perform like a 45-70 I'd get a GC version of that Keith mould.
Quite honestly my new 255 Keith 45 Colt load is about 26 grs of KIK FFFg. has more "thump" than my go-to hunting (backup) load, is very accurate and loads of fun to shoot.
JMHO, of course.