7mm Airgun- Concept Only, Design Needed!

[Technician1002]

The really small ones are thinner metal than the DOT approved refillable tanks. As such they have a lower burst pressure. To prevent fires, the safety release valve must remain closed at normal temperatures encountered in normal use. This means withstanding desert heat (not closed in a black car) sitting in the sun. I think the relief valve should remain closed up to about 300PSI. The listed working pressure is below that. You should be fine on the small tank up to about 200 PSI. Less if it gets rusty inside.

[MisterDoctor]

Aside from these tanks, what would be a good refillable reservoir for my gun? I don't wan to regulate, so one shot tanks are what I'm looking for. Since the projectile is so heavy, I'll need more pressure than 200psi. Any suggestions?


Also, I changed the caliber from 7mm to 9mm. I'm using steel balls for now, soon changing to those bullet-shaped fishing weights.

[jackssmirkingrevenge]

Fire extinguisher

Also, bullet shaped fishing weights from an unrifled barrel aren't going to be very accurate beyond point blank range.

[MisterDoctor]

Fire extinguisher

Also, bullet shaped fishing weights from an unrifled barrel aren't going to be very accurate beyond point blank range.

Lovely. I have several c02 tanks I can use. Also, regarding rifling, can I make my on rifled barrel? If not, I might just order an actual .357 barrel blank from Green Mountain Co. I remember seeing a thread on rifling spud barrels, can I apply this ghetto method to my stainless barrel?

[jackssmirkingrevenge]

I might just order an actual .357 barrel blank from Green Mountain Co. I remember seeing a thread on rifling spud barrels, can I apply this ghetto method to my stainless barrel?

For less than $100, I would go for this, much less heartache for a much better result.

One thing to keep in mind though is that a jacketed bullet needs quite a bit of force to be pushed through the rifling. Considering that airgun pressures and velocities are closer to black powder firearms, I would be more inclined to go for something like this: http://www.gmriflebarrel.com/productdet ... ?id=124012

[MisterDoctor]

One thing to keep in mind though is that a jacketed bullet needs quite a bit of force to be pushed through the rifling.

If you look at the rear of the weights I'm using, they are hollowed out slightly. Which will allow the air to expand the pellet to catch said rifling. Besides, a .40" ID would be WAY overbore for a .357" round to fly through.

Currently buying a .380 ACP magazine to convert to take my .357" lead, considering they are nearly the same size. Realizing there is no other way to go, I'll copy the MK III design- making everything stainless. I'll extend the receiver, to allow for rails and such. I need to buy a high-pressure qev, and a large reservoir. Probably barrel-length (25 inches), to hold about 300psi for a few shots. Busy making the design in MSpaint, due to lack of a better design program. Be back soon.