How was the velocity BEFORE you replaced the piston seal? If the velocity was low before they yes, your spring (or gas strut) probably needs replaced. If it did not drop until you installed the seal you may need to size the seal. If a seal is too tight it will have a significant effect on velocity. On the other hand if the seal is too small the velocity goes up but the piston will stop violently at the end of the compression tube. It's a balancing act.
Please do. Considered getting one for the Gamo I have but after trying to push a pellet through the barrel to check for tight spots and having it fall all the way through with no help from me, the one I have has a way bigger issue than the gas ram...lol.
.177. I bought it for $25 at a yard sale and it was already kinda beat on. There's a thread farther down in the Gate on it. Been fun tinkering and just more reason to...lol.
I installed the Custom Air Seals Gas Ram. I didn’t gain any velocity. It installs in reverse. Meaning the base of the ram fits in the piston and the top of the ram installs in the trigger group area. Regardless I am very pleased with the overall results. Huge std deviation improvement after the hone and new seal. I also installed the Airgun Detectives trigger screw. Made a noticeable difference.Here is how it’s performing now.Gamo Bone Collector .22CPHP 14.31. 672.62. 672.63. 672.64. 669.35. 669.3Avg FPS=671.28ST Dev=1.80Ft Lbs=14.3