I've been wanting to build a tanker for awhile. I decided to build a 9mm tanker carbine. I've only got to do a little testing but not to bad for a low powered thumper bottle buster. It has a 16.5" .356 barrel. Modified crosman breech with pictany rail. Full barrel shroud is 1.0 OD. Rear cocking assembly. It has an older 13XX trigger group that I refinished. The trigger group came out really good shimmed the trigher and has no slop at all. Installed a silver trigger shoe. I think it came out good and fun to shoot.
58 grn Enjin pellets
Tank Fill 2800psi End 2400 psi
Tank Reg out put psi 1100 psi
I did shot one 75 grn WC and it was 500 fps.
Could juice this thing up a bit but I'm going to have to get some bevelled spring for the regulator to increase the PSI.
By the way this gun will be up for sale shortly