GBB 'gas mileage' decrease??
 

Hi ASC, looking for help from some of the GBB guys here.

I have a KJW KP-05 (double stacked 1911). For the first 4 months of usage the 'gas mileage' was excellent, 2-3 mags worth on a single fill.

I took it out after 4 weeks of storage, gassed it up and now it consistently gets 4 individual shots per mag before the mag runs dry. There is no excess gas venting from the barrel or ejection port. All mags and gun were lubed and filled prior to storage.

Has anyone else run into this problem? It seems pretty bizarre considering I'm using a new propane bottle. I will be buying another bottle tomorrow incase it's the new bottle that is the issue.

Any help on this would be appreciated, I'm purplexed on what is happening. (Checked all mag flow valves for smooth movement and valve knocker for issues, all look fine)

I suppose it could be a mechanical problem with your gun, but this generally a temperature problem for me. If it's colder than +21 Celsius wherever your shooting it, it will perform sub par.

My tm 1911 mags get 6 shots in one fill in +17 Celsius, but they get 2 mags worth of shots in + 24 degrees. Hope that helps.

edit: or it could be lack of silicone oil.

It was 21 degrees room temperature with silicon lube both in the mags from storage and in the bottle.

It's happening with all 4 of my mags. so I am guessing it's either a fuel or mechanical issue with the gun.

Which propane adapter are you using? If it's the current AI plastic adapter, make sure the tank is compatible. Use the probe on the side of the adapter to test if the adapter is opening the tanks valve. There is a chance that you're not getting as much gas in the mag as you think you are.

You can also eliminate the gun as the issue. Break it down, clean, inspect and lube.

Worst case is bring it over to CAPS on Friday night and we can have a look at it. :)

Definitely try the new bottle first....

Chilling the mag sometimes helps me. There were times where I'd fill up a mag and only get a dozen shots. I'd fill it a couple times, rapid fire it, and fill it again till the magazine became cold. Then it fills nicely, you can really hear the gas transferring.

Yep. I have this issue with my M11 mags and sometimes I just have to fire off the whole mag of gas and then refill it before it will take a full fill.

In gas guns, cold mags = bad.

... you really need to read a bit more.

They're talking about filling.

Cold mag + warm tank = good fill.

Cold mag + shooting = not as good.

or more simply put,

cold compresses
warm expands

For filling, you can fit more gas into a cold mag.

+1.

Yea, filling the mag when the mag is cold makes a good difference. I also like to put a hand warmer pack on my propane tank to help as well, since it's so darn cold here. Another thing that helps with gas efficiency is mag lip shimming.

Read the following link on how to shim mags:
http://www.airsoftforum.com/board/WI...#entry18271499

This made a HUGE difference in my TM G17.