Hi, I was wondering if anyone had this issue. I bought a used benjamin trails np2 in .22. I chronographed at 810 fts with about +-10 ftps variation using untra premier 14.2 grain pellot. This is pretty good for this rifle based on others reviews. I decided to clean the gun up and add a new seal. The stock seal was very very tight. Tightest I have encountered. The compression chamber was totally clean and dry. The seal look ok except for signs of some deterioration. I added a new aftermarket oversized seal with moly and it is considerable looser. It slides nice and does compression fine. It is about as tight as found on most air guns. The ftps went down to 730 fts. I put the old seal on again, it is much harder to get back on the piston than the aftermarket one. It now fits even tighter than before and my velocity decreased to 650 fts. Next I'll going to size the factory seal to the level of tightness it was originally. I'm not sure why it fits tighter than before. Has any np2 people had this issue.
