So this is the reason why my .172 Impact went from 1030fps down to 950fps. all because i cut the breech shorter and cut the leade where the rear band enages the lands upon chambering. 28.15” down to 27.5” barrel length too. i thought my Impact broke! The Jump leade gave 2 inch wide prints at 100 yards.
The straight flute reamer is a fail. It keeps falling into the grooves and trying to take a big bite. I'll have to get the spiral flute cut down and try again.
Quote from: darkcharisma on November 20, 2021, 01:13:32 AMSo this is the reason why my .172 Impact went from 1030fps down to 950fps. all because i cut the breech shorter and cut the leade where the rear band enages the lands upon chambering. 28.15” down to 27.5” barrel length too. i thought my Impact broke! The Jump leade gave 2 inch wide prints at 100 yards. Did the accuracy improve with increased contact to rifling?