Hehe, I know your pain. I lost mine too.
I'm in the process of making a new one with this material I got on Amazon. It's cheap too.
UHMW (Ultra High Molecular Weight Polyethylene) Round Rod, Opaque Off-White, Standard Tolerance, ASTM D4020, 3/8" Diameter, 24" Length
The piece can be no longer than the stud that it goes on.
Once I get my gun working and back together I'll let you know.