I tested out some 10mm reloads the other weekend and was taken back a bit by its recoil and pop. I was using AA#9 and bareys 155gr HBRN (Hallow Base). I worked up from 13gr to 15.25gr and never saw any flattened primers but man it was impressive at the higher grains. It even impressed the people i was shooting with and thy have been around me and my hand loads before. many claimed that the blast shook there brain. i then let a friend shoot it while i stood behind him and yes it would rattle my head. After 50 rounds i had a head ache. any one else have weird results using hallow base bullets.