Locking a gas rifle to single shot

[Gaz259]

Ive recently purchased my first gas rifle and its coming in hot. Ive been advised by a few people not to get an NPAS put in it as it decreases gas economy. How can I set it to single shot as Im not overly fussed about using it in full auto.

Should I decide to get an NPAS put in how much does it cost roughly and who would be a good recommendation to do it ?

[dadio]

Re: Locking a gas rifle to single shot

An npas won't change the gas efficiency ,they simply reduce the flow through the nozzle ,it won't make gas use go up or down as the gas is metered out by the valve in the magazine ,some older systems changed the tension of the spring on the valve knocker so it released more or less gas but that's not how npas works .there's no real down side to npas except maybe if you go for max fps it might reduce the gas that is needed for the blowback but that's at an extreme ,if you are reducing fps then it means there's more gas for the blowback system.

[Tariq182]

Re: Locking a gas rifle to single shot

As said, lower fps = more kick. Win win situation

What rifle is it? WE M4 based rifles, and maybe G36 is as easy as filing a part of the fire selector barrel off so it cannot engage auto.

[Gaz259]

Re: Locking a gas rifle to single shot

Its the G&P SAI gas blowback rifle

[Morxis]

Re: Locking a gas rifle to single shot

Guys, less fps does not equal more kick. It's not the mag valve that dictates the efficiency.

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You could cut a coil at a time off the rocket valve spring to reduce fps.

[dadio]

Re: Locking a gas rifle to single shot

Its difficult to un cut a rocket valve spring to adjust to differing temperatures though ,its still fair to say that the magazine valve meter's out a given amount of gas that is the divided by the rocket valve between the nozzle and the blowback engine ,by reducing the flow through the nozzle there will be more directed to the blowback engine ,or by changing the impact delivered to the release valve in the magazine it will release more gas ,this will increase power to the BB and blowback engine ,in short there's many way's to skin a cat .

[Sprockets66]

Re: Locking a gas rifle to single shot

Fit the NPAS, you can then adjust for different gases, temperatures and site FPS. A win all round.

[Boo-Sabum Ben]

Re: Locking a gas rifle to single shot

As said above. All the NPAS does is move the floating valve around, so changing the divide between gas going down the muzzle, or going into the rear of the bolt

[Tariq182]

Re: Locking a gas rifle to single shot

Guys, less fps does not equal more kick. It's not the mag valve that dictates the efficiency.

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You could cut a coil at a time off the rocket valve spring to reduce fps.

We're not talking about mag valve. W're talking about how the NPAS works.

[Morxis]

Re: Locking a gas rifle to single shot

That's not how an npas works either guys. The gas comes out of the router in the mag. The valve is locked open at this point (different methods are used depending on whether its WA, WE or kwa etc). The npas will allow more or less gas to get through to the bb (changing the fps). When the bb leaves the end of the barrel the pressure changes inside nozzle and this is what shuts the rocket valve which closes off the barrel. Now all the gas that comes out pushes the bolt back until the bolt hits the mag valve disconnect mechanism. Only at this point will the valve in the mag close. This is the reason a mag will vent all its gas if the bolt (or slide in a pistols case) does not travel back far enough to hit the valve release.
So the recoil will always be the same regardless of the fps of the gun. There are always 2 stages with a gas gun. 1st is the bb being pushed by the gas until the rocket valve seals the barrel. 2nd is the blowback stage which also disconnects the mag valve from being held open.
It is true that a high flow valve will increase fps but that's just because you are allowing a less restrictive path for the gas to go through. It would also have the same effect on recoil, more gas pushing the bolt carrier or pistol slide back.

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But anyway. Just fit an adjustable npas and you will be all good.