Hello guys and gals. Not sure if this is the proper forum for my question but here goes.
I have a new avenger in 22 cal. Have shot well over 1000 pellets. I cannot come anywhere near the 15.89 gr Diablo tune shot count. I have tried reg settings of 1400, 1600, 1800 and 2000. Hammer springs of 1.5 to 4.0 ( at .5 increments). I have made all shot strings over my Chrony and notice a consistent drop of 400 psi of fill pressure every 10 shots. I always start at full fill 4350 psi. Best I ever got with today's setting from RL Airgun supply suggestion ( where I bought it new) is 4350 fill, 1900 reg set, 2.5 HS turns. Off the reg at shot 40. Continued to shoot thru shot 70 where reg was 1100, tank pressure was 1400 and velocity dropped to 800 ft/ sec. When I contacted RL Airguns I was told perhaps it's the difference in Barometric pressure. I live in Pewaukee WI and the altitude is 1950 ft above sea level. Florida is 100 ft above sea level. I cannot accept this as the major factor.
I have no drawings and as a retired engineer, I can only guess what the problem could be. No external leakage and air pressure holds solid overnight. Perhaps this consistent air loss is due to valve not freely moving to it seated position and or weak return spring.
I believe there is a problem with my particular rifle and am looking for any help or opinions. My first PCP so not alot of background.
I kindly thank you in advance.
Tom Makouske