Clark shoots "Ruger" loads in his Uberti, but that's Clark.
The C.I.P. specification for .45 Colt is about 16000 psi (whatever number comes out to an even number converted to atmospheres. I think it's 16670) I would be comfortable shooting a load like that in any well-made post-war gun. Probably about 10 grains of Herco with a 250-ish grain lead bullet, but that's a guess.