Velocity variations

[amc577]

Some interesting observations via chrono today with a 303. reduced loads.. Cold barrel...10 rounds..copper plated bullet. First shot was 200fps less than the next 9 shots, which were all very similar in fps.

With lead bullet, cold barrel, first shot was 150fps faster than the next 9 shots! If shooting comps, always put first shot into sand!

amc577

[dodgyrog]

I always finish the cleaning of my barrels (for cast boolits) by applying Fastex oil - this removes the drag on the boolit on the first firing.
Westlander sold this product at one time. I first used it in my pistol days to get the velocity of my boolits up for practical pistol shooting.