Rugers can be loaded pretty hot safely enough but I for one dont see much point in trying to make a magnum out the standard .45 Colt. BUT, you should be OK with 23 grains of 4227 with a 250 grain bullet. I know of people that used more than that with even heavier bullets but as I get older I find that I dont need or like heavy loads near as much as I did at one time. I get beat up a lot quicker than I used to.