Beomagi

17/32 is smaller than 9/16, it will be even tighter. That said, I would experiment with a tighter dart fit, as well as looser. PETG might actually be about the same as 9/16 though, I'm not sure off the top of my head but they're pretty similar.

Try a tighter barrel, I have a feeling that might actually help. I use a tight barrel on air blasters with stock darts, and I don't usually have them split.

I have some 17/32 I can try, and some cpvc as well on the way. what PETG tubes would you recommend?

It's a 3 way (which of course is not really necessary), and yes, the little extra air is redirected to the barrel (check valve to prevent blowback). I believe it would make more of a difference with a smaller tank. Figured if I can fire a dart on that air alone, I may as well use it too. I know it's not making much of a difference. Just a little peace of mind.

Well, here's the blaster currently. Realized I can remove the pump hose. Figure I can strengthen the point where it screws in by building up there with metal epoxy or something.

Thanks for the links guys. I can use the shell idea with another design. I'm already getting parts for another

This is turning into any of my other hobbies where I'm spending as much time building/modding as playing with whatever it is I wanted to play with.

Given your condition of slight modding, I'd suggest anything that fires mega darts, or multiple darts, and had adapters to fire a single regular dart.

E.g. Cycloneshock with worker barrels (or brass it yourself), or sledgefire with an adapter for single shot.