Thought I'd share my Delta 68 with y'all. I put a dummy co2 in the changer, and then ran macro line under the grip to a straight macroline fitting threaded into a female pipe union I epoxied into a hole drilled in the bottom of the grip. I also modified the spring feed so I can load it without having to remove the rear plug. I also have a spyder spring kit to play with velocity.
My dremel got away from me a couple times. I've since painted the tool marks black.