as you could have guessed I am makeing a spear gun. I was wondering if I have a 8mm barrel(spear track) and I want to make an enclosed gun what shuold the spear deamete should be? also if I have a 8mm rail and I want to make an open track gun what should speras deameter be? in aditon to this, could you tell me what kind of stainles steal shoul I use for rail/barrel and for the spear (number)? besides wich profile is better for enclosed gun?
P.S. sorry about all the mistakes and thank yuo for your anserws.
