I am assuming you are suggesting a circumferential groove on the OD of the piston seal near the "crown". I wonder if this hasn't been tried before.
I have heard of metal piston rings being used years ago. What the heck, I will give it shot on my B30, since I have an oversized CC that I bored and honed.
JK's Airgun Forums, moderators, and administrators are not responsible for any problems that may occur from reading or using content posted on this forum, as they are the exclusive responsibility of two parties: the person who posted it and the person who acted on said posted information.Use of our forums by people under 18 years old is allowed only with legal guardian(s) present..