Hmmm. reset your length to take it down another .003 and check diameter of your crimp at the mouth. I run .471. Lotta different factors involved here. Also. velocities run faster than Published in my barrel, it's a little fast. However, the books all show 5.3 grains running around 854fps or so. I'm running a tenth of a grain less and getting 835fps, you should be seeing more than 775fps.

How far away are you setting up the Chrono? Are you shooting through the upper third?

I will try seating it a little deeper. I would say I was about 8 to 10 feet from the chrono. I was shooting right through the middle, should I be shooting through the upper third?....I did not know that. Thanks for helping. Also, would the barrel length of the gun affect velocity?....I am using a commander size 1911.