I have 2 cast bullet designs that I use in the 45 Colt . I have an original H&G 501 , Elmer Keiths swc design for the 45 colt . It weights 255 grs . My other is the LEE 452-255gr RNFP . It casts a bit larger in diameter . I size both .454 and have no problems w/accuracy or leading my barrels . My Smith 25-5 shoots accurately with either bullet . My 3 favorite loads are 8.0grs of Ramshot Zip , 9.0 grs of WSF , 7.0 grs of 700X with either cast bullet . I don't try to " magnumize " the 45 colt . A 255 gr cast bullet @ about 900 fps will do all I need for a " walking around " load in the desert and for protection against 2 / 4 legged miscretes . Regards Paul