
The thing is, it's too weak to be used as the chamber pipe for my 100mm BFG, and I already have 2 prototype hybrids in the works (a SCH 40 4" one to test fueling, and later a SCH 80 seamless 4" one to test ignition).
Any ideas as to what to use it for would be appreciated, provided that they don't include burst disks. Even a butterfly valve may end up being used, as my budget for this summer will be largely consumed by the BFG, and I want a gun I can shoot for fun that doesn't have pathetic power. A 4x piston hybrid may be considered, but building a serviceable steel piston valve from welded parts doesn't sound like a very pleasant endeavour.
If everyone submits their ideas, I'll make a poll including the most popular ones in a few days. The winning option, assuming that it isn't impossible or horribly expensive, will be built.