Looks like I've fixed the constant problem thats plagued me since I first got into small bore high pressure guns, the sealing face always coming off. I went to a place in Brisbane called Clark Rubber and bought a few rubber door stop thingo's. They were in a cone shape and way too big so I just machined it down on my bench grinder and came up with a solid rubber piston. Since I put it in, I'm yet to have a single problem with it. When lubed up, it is extremely smooth and slides very, very well. Probably the best out of anything I've tried for a piston. Even at 300psi with 100 shots fired, the barrel doesn't cut into it at all. It's just perfect. I'm using it in my 6mm mounted pump bb gun. Yesturday I shot it at 300psi and geeez....at that pressure, the ammo pisses through anything! It's great.
I don't think I'll ever go back to my previous piston materials, just no point. To me, this is as good as it gets








