Which gas to reduce fps?

[Caveira]

OK, my new GHK AKS-74U GBBR arrived yesterday :D:D:D:D and I got round to chronoing it today.

With a warm mag (filled indoors and left about 20 minutes before firing), it was varying between 370 and 380fps. In the long run, I'll be getting a machined bolt and NPAS, but I'd like to be able to skirmish it in a couple of weeks and (while the cold may well drop the power to safe/useless levels) I want to be able to start the game knowing I'm OK if asked to chrono it.

That was using Abbey Ultra, so what gas could I use to drop the power by 30-40fps?

[mcwimbo]

Re: Which gas to reduce fps?

safe bet would be 134A, but you may not have the oomph to cycle it fully after the first few rounds.

[The Keeper of Secrets]

Re: Which gas to reduce fps?

Indeed, it's the same problem most U.S marked-aimed GBB rifles suffer. They're designed to be used with green and ultra but run at UK-hot fps'. With 134a you'll get the fps drop you're looking for, but I'd be skeptical as to the gas' ability to blow the bolt back.

[Caveira]

Re: Which gas to reduce fps?

Am I right that from low to high power, they would be rated 134a, green and then ultra?

If so, as I'm only trying to lose less than 10%, would green do the trick?

[mcwimbo]

Re: Which gas to reduce fps?

no green is more powerful typically than ultra, as Green is simply propane with added lube apparantly.

[The Keeper of Secrets]

Re: Which gas to reduce fps?

As above:

134a, Ultra, Green (Propane with silicon added), Red.

Red will kill things.

[shooter88]

Re: Which gas to reduce fps?

I suggest ultra may be able to reduce the FPS but it may not bring the bolt back,I tried 134a on my M4,it sounds very weak but I do get 340FPS: )

[Chandler]

Re: Which gas to reduce fps?

my mate used to put green gas in for a while then top it up with 134a, not sure if its safe though..
Chandler

[tom the bom]

Re: Which gas to reduce fps?

what is red gas?

[The Keeper of Secrets]

Re: Which gas to reduce fps?

what is red gas?

A very powerful gas. I don't know what its chemical forumla is but it'll blow up most gas pistols.

[LtPurcy]

Re: Which gas to reduce fps?

Red gas is known as freon22 its found in US made air conditioners

and its freaking lethal.

Robin for the moment its probably best to stick to abby ultra until the NPAS kit comes, like you said when your outside you should see a fps drop and then by the summer you can run perfectly with your npas

[JimHensonMadeMe]

Re: Which gas to reduce fps?

In my linited understanding 134a is one of the weaker gasses. From what I've read most guns are made to run on it, but some stronger built ones can handle alternatives.

[THE-ROGER]

Re: Which gas to reduce fps?

cybergun , 134a , abby red gas , abby ultra , green gas , propane