Hi all, we have No.4 HW100’s between my brother and I. No.3 of them are full length, No.1 is A carbine, No.2 of them have thumb hole stocks. Out of all of them, one of the full length sporting stock rifles appears to produce more recoil. They are all set at the same regulator pressure with the exception of the carbine one and are all producing similar ftlb. They all have adjustable hammers. The one that produces the recoil did have the restrictor removed from the exhaust valve, thinking that was the culprit, I reinstalled it but there was no change in the recoil. Firing the rifles with no pellet removes the difference. I have swapped the stocks but the recoil stays with the same mechanism. Any thoughts on what could cause the difference?