I got my 1077w about 6 weeks ago, always used pellgunoil, don’t store with Co2. I noticed leaving it sitting for even a hour, it would shoot hand throw pellet speeds for a couple of shots, then pick back up. Yesterday about 700 rounds thru it, I got it out after about 10 days and all 4 mags were between hand thrown and half speed. I called Crosman and declined to send it back. They are sending me a new valve, but that’s it. Once I open it no warranty. I’ve watched some videos and it seems simple enough. I’ve found the missing 2x5 o-ring local for the valve, so I’ll get that. Any other ideas? It doesn’t leak from the co2, just doesn’t seem to transport the air to behind the pellet like it did. Any help is appreciated