Alright, usually I throw myself into projects and don't do a lot of planning, but I am going to spend at least two weeks designing it, than a few more weeks getting down the skill on welding, and than I am going to build it:
Basically it will be a KP-3, but homemade. The only thing I won't make is the stock and a valve from a PGP.
My design is very similiar to a PGP, it will be a three-tube gun mounted on a synthetic stock, but instead of a pump it will be a bolt-action. The barrel will be about 14"-16" long and the top tube will be a 15-20 ball spring-fed magazine. I will be using the same valve and hammer as a PGP, just because I have some lying around and can't make one on my own. It will run off 12 grams.
Now my question is how would I be able to increase efficency, using a PGP valve? I am making my own bolt out of Delrin, and noticed that the KP-3 bolts were very long... does a long bolt have any pros?
I have some plans and sketches right now, and am going to use an auto-cad program once I get some details worked out. The only things that will be a problem are the welding and mounting of the trigger internals inside the stock.
I am serious about this project, so I want to start building it with exact standards in mind
Any suggestions would be great, especially ideas on increasing efficiency and generally making the design of a PGP better/more unique.