Merely considering the inconsistency in pipe inner diameter. I started each of three "pockets" in the piston skirt with a 1/4" drill bit, finished them with a 1/4" milling bit, then CA glued three pucks of "mystery polymer" I got a two foot rod of. After copious working with files/sandpaper/profanity, and honing the &^^& out of the first few inches of airtube, I got the piston with buttons into the tube. First few shots the gun felt tight when cocking, but loosened up and feels normal now. I think it's a little smoother and quieter now, with zero "ping" that was previously there at the end of the shot cycle.
Steve,When you say you cut a piece to fit, do you mean you cut a piece to wrap all the way around the outside of the piston? If so, how wide was this band?
How did you do the buttons?I've never found buttoning to slow piston travel myself.