Folks, Just got my pair of Uberti 45 colt inserts for my 20ga sxs. They appear to be quite well made and fir very well. The rifling portion is about 4.75 inches in length. Was thinking of using up some of my 45 acp cast bullets .452 230 grains or some 300 grainers using 4227. I want to be around 950 to 1050 fps. Anyone have any experience with these inserts and loads? Thanks