My bar 10 is 2.5 years old, and well used, actually, beyond well used. It is still awesome and shoots on target provided the hop bucking is in good shape. One thing, and I may have left it cocked for a few months accidentally... Took it all apart, relubed it, and did my normal cleaning routine. I just chronographed 10 shots at an average of 437 fps or the equivalent of a 130SP. I have a Laylax PSS10 150SP spring in there that is about 2 years old. Is it normal for them to wear that much after many thousands of shots or leaving it cocked for 2 months during hiatus? When I put the spring in 2 years ago, it chronographed at 510 fps, as expected.

By the way, Laylax NEO piston, trigger sear, and piston sear still look brand new 1 year after insertion and about 2000 more rounds. :)

What size o-ring does the piston take if you think it's the culprit? I have to go to the hardware store anyway to pick up a hex nut for the bipod.