... it's just KIXX has expressed interest in this project and asked to see pics.
Yeh i think high volume is important for this kind of thing...
lets put it this way, if you move up to a .40 diameter bore if it's only about 8 inches long it has as much volume as a 14" .22 cal barrel, so your probably gona want more gas flowing through there...
and a stock 2250 shoots with about 8 fpe...which isnt much to put behind a 60+ grain projectile.
Here's what im using, .35 diameter lead round ball, with a sabot made from a .410 shotgun wad.
Though of course it would work fine for blowgun darts in stock form, which is what this was originaly designed for...
In current power modded form it can put wire darts though 3/4" plywood..at 10 yards range.
and more startling still it can do the same with darts made from nails...steel spikes 2" long 1/8" thick.
Its actualy sorta scary...