[tamko]

I saw couple brand name (I'm new), and some make a long back/breech like dye, and redz. short back like syl and stiffi

what the different, and how it is different??

alan'08

[Black Label]

confused, elaborate... what gat (marker) are you shooting?

[tamko]

PMR

what I mean is, the barrel back....like the 2 pc barrel. I saw some really short back like the stiffi, and like the normal length like the dye UL


alan'08

[Castro #66]

The back length makes very little difference. What matters is the inner diameter's relation to ball size. They must be close, or the barrel must be slightly smaller than the ball to work most effectively.

Yes, underboring is ok.