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Lupus78

WE Gas Blow Back M4A1 Carbine

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Good morning people. :)

 

I just made a chrono test with full magazine (30rnds) with the gas that I have (Cybergun Blowback Gas APS3), which is pretty close to green gas for it's performance. It actually contains "Cyclomethicone - Butane - Isobutane - Propane", according to labels. The temperature was 21 degrees Celcius here at the office.

 

These are the readings that I managed to get. Our *suitcasey* chrono missed a lot of bb's, but here's what I got. The shots were about second or two apart from another and between writing down there was a longer pause (perhaps 5-10 seconds).

 

148, 150, 151 m/s

 

-pause-

 

144, 141 m/s

 

-pause-

 

150, 146, 147 m/s

 

-pause-

 

143, 145, 148 m/s

 

-pause-

 

140, 142 m/s

 

After that, I loaded the mag with bb's and shot the whole magazine empty in full auto, without refilling gas. At the end the cooldown was considerable. But even after that there was enough gas for about ten shots. Yesterday when we fired single shots and short bursts, there was no cooldown that we could detect. That is the style I will play with this gun, so I'm certainly satisfied with it's overall performance.

 

I'm also eager to hear about any outdoor range tests, since I can't provide those at the moment. At the evening when I get home I'll try to figure out how to take apart the inner barrel and swap it.

 

But before that, I will test and chrono the gun with HFC134a.

Edited by Lupus78

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HOw well does the hop up function??

 

I'm also eager to hear about any outdoor range tests, since I can't provide those at the moment. At the evening when I get home I'll try to figure out how to take apart the inner barrel and swap it.

 

But before that, I will test and chrono the gun with HFC134a.

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Darn, that's a bit on the hot side. :/ But the way it's going looks great.

 

On the other hand, HFC134a might get better, althought the 12g CO2 would be peach, as long as the tuning was easy enough, but not too easy if you get what I mean. Basically that it wouldn't be too easy to crank it to 150+m/s on the field to mess the other players, because that'd be sure way to get these banned from all fields except the Far East ironman ones...

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You could go DMR and stay semi auto :D

 

Darn, that's a bit on the hot side. :/ But the way it's going looks great.

 

On the other hand, HFC134a might get better, althought the 12g CO2 would be peach, as long as the tuning was easy enough, but not too easy if you get what I mean. Basically that it wouldn't be too easy to crank it to 150+m/s on the field to mess the other players, because that'd be sure way to get these banned from all fields except the Far East ironman ones...

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Yes, it does ^_^

 

And Airsoft GI, I sure hope you guys stock this one! :D

Your prices on WE guns are usually about the same as Hong Kong retailers, so I think there will be a lot of people hoping to get one of these new gas blowback M4s from you at a price similar to that of the Hong Kong retailers but without the overly expensive shipping costs.

 

 

It looks like you can adjust it. But, it doesn't even turn. Also, ours chrono as high as 460.

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Yeah. I believe that with a proper barrel length we can get the fps down to allowed levels. The overall accuracy might of course suffer from that, but it's a compromise I'm willing to make. I hope the provided CQB-barrel will bring down the fps enough, so I don't have to resort to HFC134a or cutting down the barrel even more.

 

Here's a pic of the hopup end of the barrel, for people wondering it's type:

cqb_barrel.jpg

 

I'll keep you guys posted...

 

And about the hopup: I haven't tried to tune it, since I don't have a place where I could test it and see the results. It's raining cats and dogs outside and the temperature is +6 degrees. The storm is over at least. And I really don't want to do (more) hitmarks on our office corridor walls... I hope Jin and/or Wupjack can provide us with that information when they get theirs. And it seems really stiff, like it wouldn't move (as airsoftgi pointed out). After I've dissassembled it for the barrel change, I'll take a look at it's operation more closely.

 

And for someone asking if it's loud: Yes. Really nice metallic cycling and blast of gas. Nothing like I've ever seen in airsoft and I have no experience of WA.

 

UPDATE: I shot about 10 rounds with HFC134a, all within 105-110m/s, which is around 350fps. So with HFC134 it's on the power level that WGC is telling us. I guess they just have an error on their page. And now that the magazine has warmed up from my full auto test the HFC134a seems to work quite fine. Full auto is fun enough, which is nice. Sure it's snappier with the cybergun gas, but I'm rather surprised it operates even this good with HFC134a.

Edited by Lupus78

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FYI, I sent an email to WGC asking whether their WE will come with 2 barrels and what's the real fps they got? Below is their answer:

 

Thank you for your inquiry,

Please be inform that it should not come with 2 barrel

and the power is around 330-350fps only.

Thanks,

 

Best Regards

Allen Wong

WGC ( Hong Kong )

 

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I've been thinking about the fps-issue with green gas and wondered would it be possible just to make its metallic bb-nozzle more tight, so that it wouldn't blow as hard into the barrel. This could be done for example using some epoxy glue to block the nozzle, then when it's dry, drilling it with a small drill, widening the hole as much that is needed to find the desired flow of gas...? This could lead to aftermarket nozzles that are made for different fps needs.

 

Could it work? Or is this just a stupid idea? Only if we had some spare nozzles to play with...

 

Hopefully the aftermarket business for this rifle starts up as fast as it did with the WA. I think this gun is going to be a lot more popular, due to it's low price, full metal body and great operation out of the box. Only thing actually bothering me is the hopup, which is still a mystery. I will try to examine it tonight.

Edited by Lupus78

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Depending on the valve opening time, it could be the same or even worse: if you just make the hole in the nozzle smaller the same ammount of gas will come out, but either at higher pressure or itll take longer.

 

There's also the chance that the BB is out of the barrel before a lot of the gas still has to come out the nozzle, thus consuming the same ammount of gas, but using a smaller part of it, keeping the blowback and reducing the fps.

 

yeah, someone with wider knowledge about gas guns should answer this.

 

Anyway, WGC has it down to 340$ now. Sweet.

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Considering the fact how much the barrel length affects the fps with gas guns, reducing the physical amount of gas entering the barrel should also reduce the velocity. This could direct more of the gas into blowback system. The gas pushes the bb all the way through the barrel while expanding and not just at the beginning. Similar thing happens with AEG's, which need a certain amount of cylinder volume if the barrel is long. In AEGs there is no gas that expands, but a large chamber of air that is pushed into the narrow barrel. If the cylinder doesn't have enough volume to cover the barrel, the push ends before the bb is out the barrel. Which is why there's no point installing insanely long barrels into AEGs. In gas guns there's usually so much gas used that there's no practical limits to the length of the barrel.

 

I really have no idea what this kind of a mod would do and how easy or hard it would be to get to desired effect and would it affect the working of the hopup etc. I guess no one has tried anything similar, since too much power usually hasn't been the problem(!). And external rigs always have their own regulators. But as I said, just the CQB-barrel might lower the fps enough, without any other modifications needed. When the CO2 mags are released, we might have to think again how to reduce the fps to tolerable levels.

 

And these could also be ramblings of a madman. The amount of gas I've released with WE M4 is affecting my brain functions... :wacko:

 

PS. I would REALLY like to know what kind of changes are made to WGC versions, if their gun really has only 350 fps with top gas.

Edited by Lupus78

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True, but you see: by making the hole, wich the gas has to go through, smaller, you do not reduce the volume of gas being pushed into the barrel, you just change the pressure and time to get out.

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It's not entirely necessary to cut down the entire barrel I think. Making a port on in the barrel large enough that you essentially bleed off all pressure at that point would do the same thing (i.e., equalize pressure with atmosphere at best case, or drop pressure dramatically in the worst case).

 

Obviously, the larger drop in FPS, the earlier you cut the port. But that's really an awful waste of gas.

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According to WE's message, WGC's version is Asia version and ours is Export version. So the power is different to our selling version. And our package is comes with 2 inner barrels, one for Carbine and one for CQB.

 

A good news of the spare mags, they will available in this 2 weeks. Price is US$35@. For the CO2 mag, they will available at January, 2009.

 

For anyone who received the WE GBB M4 from us, please let me know when you have any problems on it. We'll fully support for parts maintenance and technical support.

 

Thanks

 

 

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According to WE's message, WGC's version is Asia version and ours is Export version. So the power is different to our selling version. And our package is comes with 2 inner barrels, one for Carbine and one for CQB.

 

A good news of the spare mags, they will available in this 2 weeks. Price is US$35@. For the CO2 mag, they will available at January, 2009.

 

For anyone who received the WE GBB M4 from us, please let me know when you have any problems on it. We'll fully support for parts maintenance and technical support.

 

Thanks

 

Now THATS cool. WE gas offerings have always been a crapshoot in the past. The scarce supply of spare parts was enough to turn off ALOT of customers. I really hope to see that changing with the release of this GBB rifle.

 

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Thank you Airsoft Buddy!

 

I've been really happy with my purchase so far! I think your customer service is exemplary. Keep up the good work! It is REALLY important that there's a support that we can turn to when something breaks down. And good to know the CO2 magazines will be coming. I really hoped they would have been here earlier, since it's getting too cold outside for us Finns to use our regular gas guns. But as with any product, I wish they are developed and tested properly before release.

 

UPDATE on my preview:

I haven't been able to remove the hopup unit and change the barrel. I believe I need to disassemble the whole delta-ring thingy and the front section. So I have to study more how to do that. But not right now.

 

I also chronoed the gun again using HFC134a (21 degree temp) and my favourite G&G 0.28g bb's (which are actually more close to 0.31g according to weighting). The velocity was quite steady 96-102 m/s, which relates to about 1.5J power. That is just PERFECT for me, since the places I go to have 1.6J limit. Hooray! As you can see, gas guns gain more power when using heavier bb's. They take longer time in barrel so when they finally come out they have more inertia than lighter bbs.

 

On the other note: I've been in contact with SAA and he said there are modifications that can be done to drop the power even to 0.7J with using green gas. Interesting to see development on that department.

Edited by Lupus78

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Well this suggests that certain parts can just be replaced from the Asia version to the Export version to make it slower, and these part(s) have already been made. Hopefully its something not too complicated.

 

They take longer time in barrel so when they finally come out they have more inertia than lighter bbs.

 

I will go off topic for a bit. I've heard this a lot of times. Though it seems intuitive, I believe it is wrong. First off "more inertia" just means more mass. Yes, a more massive BB has more mass than a less massive BB, but it has nothing to do with how long it spends in a barrel. I think by inertia, you meant momentum.

 

Second, assuming an ideal (frictionless) operation, no energy is lost. That means all of the potential energy stored in your gas as pressure (above atmospheric pressure) is transferred to the BB. This means that same gas, same pressure, same BB muzzle energy. This example is clearer with an AEG or something that rides off of a spring, since we are all more familiar with the concept of potential energy when it comes to a spring. Same spring, same compression, same muzzle energy on the BB.

 

Another way of saying this is that work done on the BB by the pressure of air (which equals its kinetic energy at muzzle exit) goes as Force * Distance Applied. Now, this force, the pressure force, does not depend on velocity, only position along the barrel. So its obvious that for the same pressure force, and same barrel length, the net work is the same, regardless of the BB mass.

 

So why is it that higher mass BBs have greater muzzle energy? Well, in the real world, there is such a thing as friction. Generally, friction goes as velocity, or in the case of drag, velocity squared, and is a force that opposes motion. So, since the larger BB is more massive (it has more inertia, like you pointed out), it accelerates slower from the pressure force, and hence it's velocity in the barrel is always slower that that of a less massive BB. This means Ffric on the more massive BB is always less than Ffric on the less massive BB, hence, the more massive BB loses less energy to friction.

 

I hope that dispels this "more time spent in the barrel" myth.

Edited by slu

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Thank you Airsoft Buddy!

 

I've been really happy with my purchase so far! I think your customer service is exemplary. Keep up the good work! It is REALLY important that there's a support that we can turn to when something breaks down. And good to know the CO2 magazines will be coming. I really hoped they would have been here earlier, since it's getting too cold outside for us Finns to use our regular gas guns. But as with any product, I wish they are developed and tested properly before release.

 

UPDATE on my preview:

I haven't been able to remove the hopup unit and change the barrel. I believe I need to disassemble the whole delta-ring thingy and the front section. So I have to study more how to do that. But not right now.

 

I also chronoed the gun again using HFC134a (21 degree temp) and my favourite G&G 0.28g bb's (which are actually more close to 0.31g according to weighting). The velocity was quite steady 96-102 m/s, which relates to about 1.5J power. That is just PERFECT for me, since the places I go to have 1.6J limit. Hooray! As you can see, gas guns gain more power when using heavier bb's. They take longer time in barrel so when they finally come out they have more inertia than lighter bbs.

 

On the other note: I've been in contact with SAA and he said there are modifications that can be done to drop the power even to 0.7J with using green gas. Interesting to see development on that department.

 

Thanks for your kindly review for this WE GBB M4.

 

I'm asking the factory of WE about how to change the inner barrel with the hop-up unit. I will post here to let you know tomorrow. Please let me know if any places need to improve for this WE GBB M4, I will pass your concern to them for improvement.

Edited by Airsoft Buddy

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Finally recieved my WE today also, seems to be a nice gun, my magazine is also leaking dunno why.

 

Ive taken a few pics of the rifle, my CA M15A4 is also posing in some of the pictures

 

 

 

IMG_0590.JPG

IMG_0591.JPGIMG_0596.JPGIMG_0597.JPGIMG_0600.JPGIMG_0603.JPGIMG_0604.JPG

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Thanks for the explanation, slu. I believe that you're right. ^_^

 

Back to topic - When I dissassembled the gun, I really tried to turn the "hopup adjustment" with my finger tips. It doesn't move even a millimeter and it's frozen rock solid. I can see a hopup there, when I look through the barrel, so it's definitely there. I'm just starting to believe it's actually a rigid hopup, not adjustable. Hopefully Airsoft Buddy can clear things for us... And while I look at the internals, I have to say they're rather good quality stuff. I would imagine first thing to break would be the bolt stop. But there's no evidence of that, yet. I think this gun is just about solid as it can get.

 

Oh, I almost forgot. The magazine has stopped leaking by itself. It seems that when I fill it all the way, it might start to leak, but after few shots fired, it stops. And it was really quiet anyway, so nothing major.

 

And for the screws: The flash hider screws on clockwise and detaches anti-clockwise. Ain't that same as positive?

Edited by Lupus78

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True, but you see: by making the hole, wich the gas has to go through, smaller, you do not reduce the volume of gas being pushed into the barrel, you just change the pressure and time to get out.

 

To a good approximation yes you do. Ideally the amount of pressure being applied to the reservoir walls, and hence the area in question that opens up is uniform. So changing the size of the hole doesn't change the amount of initial pressure that's applied "through" the hole.

 

The amount of time is kept the same assuming you use the same hammer mass and spring, etc. So when you reduce the size of the hole you effectively reduce the amount of gas in volume and number of molecules approximately proportional to the hole size, i.e. 0.5 x intial area (or 1 over root 2 of the initial radius) would result in roughly half of the gas molecules passing through the hole in the same amount of time. This is because the size of the hole doesn't change the pressure differential (pressure inside reservoir - 1 atmosphere) and so the diffusion rate should be roughly the same per area.

Since the amount of pressure is proportional to the number of molecules present, you would effectively get half of the pressure behind the bb and hence half the force and subsequently half of the acceleration of the bb. Assuming the same travel length this gives you about (velocity for 0.5 size hole) = (1/root2) x (velocity for full size hole), or about 29% velocity reduction.

 

Of course the real system is quite dynamic, and I'm assuming the acceleration is constant throughout the barrel, and also lots of other things, but it's still a good approximation.

 

So to summarize: Reducing the hole through which the gas travels will likely reduce the muzzle velocity.

Edited by Lt.Fenix

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I got a question (again) :D

 

I removed the pistol grip, and a spring popped out from a little hole in the lower, looks like it has something to do with the fire selection switch.

 

However I was just wondering if this setup is similiar on the RS model?

 

And is this "spring thing" compitable with pistol grips made for RS guns?

 

Pictures:

 

IMG_0607.JPGIMG_0610.JPG

Edited by xx-treme

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I got a question (again) :D

 

I removed the pistol grip, and a spring popped out from a little hole in the lower, looks like it has something to do with the fire selection switch.

 

However I was just wondering if this setup is similiar on the RS model?

 

And is it compitable with pistol grips made for RS guns?

 

Pictures:

 

http://www.home.no/energybar/m4/IMG_0607.JPG

http://www.home.no/energybar/m4/IMG_0610.JPG

 

 

We have been told numerous times that it should accept real steal grips. As to the spring, I dont know what that'd be fore in the inside! You can probably find the spring (use an AEG motor, specially if you have a Turbo3k/Guarder IFTU/G&P M160/Systema Magnum).

 

If you put the grip back on does it still work normally? :)

 

EDIT: Quoting pics = fail

Edited by UrPeaceKeeper

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We have been told numerous times that it should accept real steal grips. As to the spring, I dont know what that'd be fore in the inside! You can probably find the spring (use an AEG motor, specially if you have a Turbo3k/Guarder IFTU/G&P M160/Systema Magnum).

 

If you put the grip back on does it still work normally? :)

 

EDIT: Quoting pics = fail

 

Yea I know a RS pistol grip will fit, maybe I didnt formulate my question very good.

 

I was wondering if the RS pistol grips are compitable with the "spring thing", thought maybe someone who has a real ar15/m4 would know.

 

Without the spring the fire selection switch was all loose , so the spring is for that purpose.

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Yea I know a RS pistol grip will fit, maybe I didnt formulate my question very good.

 

I was wondering if the RS pistol grips are compitable with the "spring thing", thought maybe someone who has a real ar15/m4 would know.

 

Without the spring the fire selection switch was all loose , so the spring is for that purpose.

 

Is the safety dentent spring the spring you mean

 

Below is a real steel photograph...

 

http://shanedaughtry.com/images/Safety%20Detent%20Spring.gif

 

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