try this it works for me an I shoot 2/50 gr pellet 777 Hornady sabot (black) Hornady XTP mag 300 gr HP (some 45 cal. bullets are as large as .454 for use in a 45 Colt down to .451 for 45 ACP)
I am currently using .452
Brush your bore with a brass brush from the breech end every 4-5 shots, spray Pam cooking spray in the breech end up from the breech plug threads forward about 2", the oil burns off clean and stops scorching, wipes out just as easy as your favorite cast iron frying pan. Uly