What You'll need:
5/8 ID tubing for sheath(I used PVC)
5/8 OD, 1/2 ID Tubing for barrels (I used cpvc)
Open your splitfire:
Cut down your tanks and sand them till they look like this. While you're at it plug your pump:
Take your 5/8 ID tubing and cut it to 5" long. Then cut a slot 1/4" away from the back and 1-1/2" forward to create your breech opening. Be sure to make 2.
Glue them onto the tanks. Make them centered.
Dremmel out the supporting walls of the shell until the assembly fits inside the shell without any resistance. The shell halves should stay together if you took out enough material.
Finally line up your breech and mark where to cut on the outside of your shell.
Insert 8" of your barrel material into the sheaths and you're done. You can put an O-ring with an OF of 5/8 into the sheaths if you want.
I managed to find some good fitting PVC at my home depot. PROTIP check the conduit PVC. it's tolerances are much looser. Of course you can use whatever fancy materials you want from mcmaster and make a clear breech.
Edited by andtheherois, 05 December 2012 - 11:41 PM.