GBB M9 Help

[Logical Airsofter]

Hi all,

My M9 back up pistol has been playing up. It wont lock the slide back when the magazine is empty and the gas seems to be let out in varying amouts each time.

The mag is gas tight by the way.

Thanks

[PureSilver]

Re: GBB M9 Help

Why don't you start by telling us who made the gun? If it's modified? What kind of gas you're using? What kind of temperatures you're trying to play in?

[Logical Airsofter]

Re: GBB M9 Help

I believe its HFC.
Its not modified at al.
Im using WE GREEN GAS and I would say it was about 10oC when I used it.
Its also full metal.

[Sidneyious]

Re: GBB M9 Help

That's very cold for green gas, try purging the mags of air and you can over charge the mags leading to excessive discharge and then excessive cooling.

When refilling make sure the mags are somewhat warm as a frozen mag won't take in as much gas because of condensation.

[PureSilver]

Re: GBB M9 Help

I believe its HFC. [...] Im using WE GREEN GAS and I would say it was about 10oC when I used it.

OK, so without being unkind, it is an ultra-low-budget gun made of cheap, dense pot metal; it's not exactly surprising that it runs like shit in cold weather. If you want to shoot a gun in cold weather with propane, buy a higher-quality gun, preferably one with plastic moving parts (like a TM), because those are more gas efficient. If you want to shoot an inefficient metal pistol in cold weather, you need higher-pressure propellant, preferably CO₂ (which requires special magazines). Like Sidneyious says, 10°C is quite cold for propane.

When refilling make sure the mags are somewhat warm as a frozen mag won't take in as much gas because of condensation.

This sentence makes literally no sense whatsoever. Condensation is desirable; you want as much liquid in the magazine as possible. Liquid is denser than gas, so you'll get more fluid 'because of condensation', not less. People who don't care about wasting gas/the environment routinely partially purge fluid vessels to cool them down ('freeze' them) before filling them, because it drops the pressure in the vessel, creating a greater pressure differential between the source vessel and the recipient which means faster filling.

[Sidneyious]

Re: GBB M9 Help

OK, so without being unkind, it is an ultra-low-budget gun made of cheap, dense pot metal; it's not exactly surprising that it runs like shit in cold weather. If you want to shoot a gun in cold weather with propane, buy a higher-quality gun, preferably one with plastic moving parts (like a TM), because those are more gas efficient. If you want to shoot an inefficient metal pistol in cold weather, you need higher-pressure propellant, preferably CO₂ (which requires special magazines). Like Sidneyious says, 10°C is quite cold for propane.



This sentence makes literally no sense whatsoever. Condensation is desirable; you want as much liquid in the magazine as possible. Liquid is denser than gas, so you'll get more fluid 'because of condensation', not less. People who don't care about wasting gas/the environment routinely partially purge fluid vessels to cool them down ('freeze' them) before filling them, because it drops the pressure in the vessel, creating a greater pressure differential between the source vessel and the recipient which means faster filling.

And more wasted gas use, the tank can only hold so much.
I have had this problem with my msk mags, I would get 5 or so over gassed shots then 5 normal shots then maybe 3 or 4 very weak shots.

Propane in 70*f with 40% or so humidity. If I let them warm up and recharged as normal I would get 30 full power shots, no over gassing and no weak shots till the mag was halfway through the second round of bbs.

[Logical Airsofter]

Re: GBB M9 Help

Yeah, okay cheers guys.
And yeah HFC is an awful brand but it was my first GBBR and is now just a back up. I run a TM G17 and I love it.
Quick question; when using propane how do you 'prep' a gun for propane use? Cheers

[Sidneyious]

Re: GBB M9 Help

I just add silicone oil to the propane valve, screw on the adapter.

Usually good for 5 rifle mags about 8 pistol mags

[Logical Airsofter]

Re: GBB M9 Help

Okay cheers; and where do I get this valve? Do Z1 sell them?