Vortex block material

[pneumaticcannons]

just take a bb or two with you to the shop so you know it will fit.

ya thats exactly what i do. I used an aluminum tube i got from hobby town USA when I visited the states last winter. It worked OK but from then I tried a tight bore and the difference is pretty big as Gun freak said.

[stuffbuilder]

I'm not really concerned with accuracy, since the thing is going to be more of a flamethrower than a gun. Also what kind of pressure is the bb chamber usually subjected to?

[Gun Freak]

Not much since the air goes right out the barrel. Depends on your chamber size and valve, but less than 50% most of the time.

[pneumaticcannons]

If you're using a blowgun and a moderate sized chamber, then the pressure is very low. This is why people use long barrels and detents in bbmg's

[stuffbuilder]

I'm using a pistol grip blowgun as a trigger; the chamber is a 2 inch tee with a 2 inch coupling attached to one port. I'm thinking about using a 509mm airsoft barrel I found online for a good price

[Gun Freak]

Hm... I would reccomend a smaller chamber, that one sounds like its a bit on the large side.

[stuffbuilder]

The only reason I'm using such a large chamber is because its part of an old piston valve that didn't work but I didn't want to waste. I am considering making some sort of conical insert that makes it easier for the bbs to fall down to the vortex block, so I'm thinking that will take up at least some of the space. Is a big chamber a bad thing other than the fact that it takes a lot of bbs to fill?

[Crna Legija]

bigger chamber + same input pressure=lower chamber pressure.

[stuffbuilder]

Does chamber pressure matter? I would imagine that most of the power would come from the bbs spinning in the vortex block on the stream of air and the air escaping out the barrel instead of from chamber pressure. I mean the air doesn't have anywhere else to go but the barrel right?

[Gun Freak]

The vortex helps with feeding, the air pressure does the pushing. More pressure = MOAR power.

[stuffbuilder]

What size should the outlet hole in the vortex block be? Should it be just big enough for the bbs to fit through, or should it be larger so its easier for them to line up and then taper down to the size of the barrel?

[Gun Freak]

Drill the hole equal to the OD of the barrel.