qev

[pat123]

I am looking for a qev that is either 1" or 3/4" for a shotgun I want to make. I looked on mcmaster but their qevs are only rated to 125psi I wanted more like 300psi I may have to make a piston for it.

and for a shotgun a 24" 1" diameter chamber and a 24" 3/4" barrel should be good right? does anyone know the approximate length of an average shotgun? a 3/4" barrel wold be about a 10 guage.
I want to make this as realistic as possible.

[SpudUke5]

How about a 1.5 inch qev made from aluminum?
I could sell you the one i have.

Dont worry about those pressure ratings, its metal it should do fine, but i wouldnt guarantee the diaphragm being ok under those conditions.

[MaxuS the 2nd]

Uk QEV's have been used up to 800psi, and 400psi regularly. 300psi will be fine.

[MrCrowley]

Yup, i've used American ones at 300psi, they're fine.

[THUNDERLORD]

......and for a shotgun a 24" 1" diameter chamber and a 24" 3/4" barrel should be good right? does anyone know the approximate length of an average shotgun? a 3/4" barrel wold be about a 10 guage.
I want to make this as realistic as possible.

The shortest legal barrel length for a smoothbore shotgun in US is 18"
For sporting purposes that would be considered very short.
(Shortest rifle barrel w/out being a pistol is 16")

3/4" is more like 12 ga. (about .725 ID).
Gauge actually refers to the weight of a round ball that diameter.
For example a 16 gauge solid shot or standard load of shot would weigh 1 ounce (16 ounces in a pound)
That's why the smaller the gauge the larger the bore diameter.
It's an old method of caliber definition.
IMO 24" is still short for a shotgun and very short for air powered.

BTW I often load shot type stuff in a 1"x30" and it spreads so much at close range one time I shot at a can almost point blank w/ half the barrel full and none hit the soda can (devine intervention?).
Also, I am wary of rock shot in pvc because they can sand the barrel. 8)

[SpudFarm]

you can make somekind of a chocke..
go to a milling shop and set it in a lathe and fold the front end of the barrel a tiny bit inwards.