I also purchased a 625PC 4" in December, love the gun, very very accurate. I am using a 215SWC sized to 452 over 6.0 231 in a 45 Auto Rim case and a standard primer. COAL is 1.22". Got the bullet from Montana Bullet Works and it is superaccurate in my 625 with no pressure signs, and recoil is quite controllable. Be warned that my companion arm is a Model 21-4 44 with the Skeeter load, and the AR load is comparable. This is my experience I started at 5.3 grains of 231 and worked up to 6.0.