KJW 1911 Gas Efficiency advice & help

[jordan7831]

Hello everyone,

I'm helping a friend with their KJW 1911, and the gas efficiency they are getting.
At the moment, they are able to get around 10 bbs out of a single charge of gas, well below the mags 28 BB capacity.
I'm assuming that these shots are in fairly rapid succession.

I've advised that the gas efficiency of the 1911 is not the greatest due to the limitations of the physical size of the mags, and that mags should be allowed to warm up and shots spaced out to minimize cool down. That said, my searches turn up that many users report around 15-20 shots per fill as the norm for most 1911s.

Per these threads:
http://airsoftcanada.com/showthread....911+efficiency
http://airsoftcanada.com/showthread....911+efficiency
http://airsoftcanada.com/showthread....highlight=1911

I was reading that the stock gas piston that comes with KJWs is not the best, and that upgraded pistons can improve gas efficiency.

My ask:

1. Can anyone recommend a gas piston that can help increase gas efficiency?
2. Are there any tips or techniques that can aid in increasing gas efficiency that I haven't thought of?
3. How many shots do you normally get out of your 1911?

Please take into consideration this is my friends first 1911, so they are beginning to learn the inner workings of the 1911.

For those new to 1911s, here is how to access the piston:
http://airsoftpacific.com/viewtopic.php?t=33347

More context:
https://www.youtube.com/watch?v=cyY0c6ogErQ

Many thanks in advance for your assistance!

[ThunderCactus]

Shim the gasket on top of the mag up if it's not high enough
replace gas piston, vented O-ring or cup type work best
weaker recoil spring - will increase cycle time, but decrease the time it takes to blow the slide back, thus reducing the time the valve is open

28 rounds on a single stack mag with a metal slide is pretty overzealous. MAPP gas might help, in that it has a slightly higher rate of expansion and higher pressure than propane. Of course it might also just break stuff faster lol

[jordan7831]

Originally Posted by ThunderCactus

Shim the gasket on top of the mag up if it's not high enough
replace gas piston, vented O-ring or cup type work best
weaker recoil spring - will increase cycle time, but decrease the time it takes to blow the slide back, thus reducing the time the valve is open

28 rounds on a single stack mag with a metal slide is pretty overzealous. MAPP gas might help, in that it has a slightly higher rate of expansion and higher pressure than propane. Of course it might also just break stuff faster lol

Thanks Thunder!

I'm thinking vended o ring type piston would be the easiest solution. Do you think that would increase the efficiency up to 20ish bb/fill?

Perhaps this 9ball one would work.

http://www.wgcshop.com/products?sear...&view_choice=b

Or this on
http://shop.ehobbyasia.com/fe-erupti...l#.WDT5i304Mio

[RainyEyes]

Hey Jordan,

I came into this problem before and the problem is 2 fold from my experiments.

Replacing the stock piston with a 9ball doesn't make any difference if the o-ring isn't to spec. The spec depends if your nozzle is red or blue. Blue is Gucci, red is spotty and is meant more for co2.

The WE 1911 nozzle doesn't fit in it apparently, and the stock piston is meant for co2 so replacing both doesn't even seem to be possible.

I tried shimming the magazine but it just doesn't have any effect on the gas efficiency.

If it makes you feel better I have a 9ball piston I could part out to you but both need a proper spec nozzle it seems :/

[jordan7831]

Thanks for the insight seems you have done a lot of experimenting!
If I'm understanding correctly, simply replacing the piston won't be sufficient as it will not be in spec to the red kjw co2 nozzle, thus causing gas leakage and wasted gas. But rather upgrade and replace both nozzle and blowback unit.

Rainy: For academic sakes. May I ask, with a blue ( gucci spec) nozzle and correctly sized piston. What gas mileage were you seeing.

My friend has a spare hi capa nozzle. Maybe that's a workable solution. Many thanks!

I wonder what the gas efficiency would be like if one were to put their stock tm hi capa slide assembly onto a 1911. Another interesting experiment!

[Kungpow]

Originally Posted by jordan7831

Thanks for the insight seems you have done a lot of experimenting!
If I'm understanding correctly, simply replacing the piston won't be sufficient as it will not be in spec to the red kjw co2 nozzle, thus causing gas leakage and wasted gas. But rather upgrade and replace both nozzle and blowback unit.

Rainy: For academic sakes. May I ask, with a blue ( gucci spec) nozzle and correctly sized piston. What gas mileage were you seeing.

My friend has a spare hi capa nozzle. Maybe that's a workable solution. Many thanks!

I wonder what the gas efficiency would be like if one were to put their stock tm hi capa slide assembly onto a 1911. Another interesting experiment!

I do not like advertising, however I made a video on improving gas efficiently. Most notable the KJW KP07, and other TM 1911 platforms. In summary I recommend shimming the piston head/gasket with plumbers tape/teflon tape. This would require the user to disassemble the blow back unit, and take the piston head/gasket out; and apply plumbers/ teflon tape to where the piston head/gasket rests. (Please check for nozzle to gasket fitment first before reassembly.)

https://www.youtube.com/watch?v=S4w90ZSDmLo

(This is my best shot for understanding how a GBB Airsoft gun works, but I would appreciate the feedback.)

[RainyEyes]

Originally Posted by jordan7831

Rainy: For academic sakes. May I ask, with a blue ( gucci spec) nozzle and correctly sized piston. What gas mileage were you seeing.

Unfortunately the blue nozzles were discontinued and a rarity at this point. We had to abandon the project because of a lack of parts and the upgrades we were trying were going nowhere; we couldn't get a blue nozzle.

My apologies for not having more empirical data.

I have a good feeling that a hi-capa or other nozzle that might be compatible with the BBU would be miles ahead of the red nozzle.

It might be noteworthy to mention that you will definitely get better mileage with a TM stock recoil spring and a plastic slide. The metal slide on that kjw is doing absolutely no favours for gas efficiency.

[ThunderCactus]

I mean you could jusy BUY a new Oring. Its not like they're hard to find or anything lol

[Zeroroaster]

Another option is an AIP nozzle and rocket valve. I got one on eBay last year for under 20 bucks and it fixed a couple of issues...My 1911 being a CO2 pistol I was cracking the factory red nozzles as they were freezing up. The other issue was really poor 'mileage' out of a CO2 powerlet. The AIP fixed both of these issue. I get at least 50 percent or better out of the CO2 and I haven't cracked a nozzle since. Everything else I left bone stock. One thing I did do though was polish the hell out of the rails and other sliding parts to try and reduce friction as much as possible. That also seemed to make a big difference.