Willi...Used a 260gr Partition over 21.5 grs IMR-4227 in a 45 Colt Ruger with great effect. Never clocked the velocity... I have a FA`s 500 with a 6" barrel that I feel is much better length when in the field
then a shorter barrel. However, if you looking to get rid of the ports then cut her to the 4 5/8" and go with the Colt loads. Good luck....