Shotgun Chamber or Straight from tank? EDITed help!

[CannonCreator]

I am planning on making a Airsfot shotgun. It will be full metal for high pressure, or combustion. It is going to have a 3/4 barrel with a custom shotgun shell, with multiple barrels in it. Should I make it a Propane powered Combustion or a Nitro/Co2 pneumatic?

I am looking for A good, high FPS. At least enough to go thorugh a can, at 10-15 feet away.

What do you guys think?

EDIT::

Hey guys do you think I should make the shotgun with a chamber that is filled with a on board Regged Co2 tank or have the Regged Co2 go directly to the barrel with no chamber?

[MrCrowley]

Pneumatic.

[Thursto]

Defently a pneumatic!!

[potatoflinger]

Yeah, I would say build a pneumatic.

[spud yeti]

pneumatic

[CannonCreator]

k, so you guys think I can get through a can at a 10-15 feet distance with that setup?

[noob of noobs]

Are you using real shotgun shells? As long as you use something heavy as ammo, a can shouldn't be that hard to go through. Are you going to use a piston valve?

[CannonCreator]

I am going to use 28G airsoft BB's, and I don't know what kinda valve im going to use yet.

[DYI]

ERROR 002: there is no known, stable material (that we can manufacture with our current technology), that is dense enough to make a standard sized (6mm) airsoft round with a mass in excess of 1.5 grams (should be accurate to +/- .1 grams).

In response to your actual question, I would recommend a high pressure pneumatic with a piston valve, if possible. Steel BBs would be better, but you should try to keep it below the speed of sound due to noise and accuracy issues (this shouldn't be a problem though).

[CannonCreator]

Im going to use this in games, don't want to use metal bb's

[potatoflinger]

I've just started making a small co-axial gun, ggdt says that with five airsoft pellets (.12 gram) I should get about six hundred fps. The gun is made to be portable, so I was really surprised to see 600fps. I would definitely recommend using a piston valve.

[darkmilk]

ERROR 002: there is no known, stable material (that we can manufacture with our current technology), that is dense enough to make a standard sized (6mm) airsoft round with a mass in excess of 1.5 grams (should be accurate to +/- .1 grams).

i think he meant, .28 a common airsoft weight. but i would recomend .2 much cheaper. as for piercing a can from 10-15 feet, the task could easily be done at 500 fps with a .20 but if your using .28 at the same pressure, not velocity, it will be even easier. and to put in perspective, the prssure youll need is about 115 psi to accomplish 550-575 with a decent valve. so i think a 1 inch piston valve(that way you could make a cool shell ejection feature/blow back if the piston is heavy enough) with a blow gun pilot valve runing at a 150 compressor or regged co2 would be sweet. hope i was helpful

[f.c]

going through a can is easy. my modded cloud can do it from 20 meters away. so this gun you're making should be able to. and i definetly think it should be a pneumatic.

[frankrede]

clouds also get there power from the repetitious hits of the bb's.
but then again I have put a marshmellow through a can too.

[TwitchTheAussie]

1 inch piston pneumatic with a rotating chamber for the shells. I got the idea off Turok 64, from the auto shotgun