They would sell me any length any size I wanted.I was looking for SDR-21
For GB barrel, got it no problem.
I bought the parts in 6" for a launcher w/no specific plans ,they cut 24" of pipe for me. 24" is way to long but was cheap.
Is it worth putting together? If so what length chamber?
Would you guys make it pneumatic or combustion? Yep that is a propane bottle at left.
Bushing is 3" w/insert to reduce to 2".













