I cut the barrel down a bit on the RWS 3500. It came at 19.5", and I cut it to 16".
It just felt too long and front heavy. So I broke out the hacksaw, file, sanding block, and bluing pen, and went to work.
Here's the result,
Accuracy seems the same with the 14.3gr. The 18.13gr JSB tightened up significantly.
Both pellet weights gained some speed.
14.3gr Crosman - 857 fps (+ 37)
18.13 JSB - 750 fps (+30)