I am having trouble getting a good seal from the breach. Velocity is off by about 100 FPS and you can feel a puff of air at the probe if you use the single shot tray. I have tried both the stock replacement and a viton replacement in hopes that the firmer o-ring might help. Has anyone else experienced this? Is there a specific size you have had luck with? .25 cal.
Mod Edit: Moved to PCP Airguns forum
Mod Edit: Moved to PCP Airguns forum