WE Gas Blow Back M4A1 Carbine

[jkpics]

Sorry about that, guess I am used to ppl knowing I am a *albatross*.

[ODA15]

Hey all,

 

I've just recently bought WE M4 (a gas, closed bolt version) from AirSplat about a week ago, and I've run into a problem. Unfortunately, the BB's keep jamming. I've searched through this thread and found some helpful posts that have lead me to completely take down the gun, clean the barrel, disassemble, clean and reassemble the hopup assembly, and also adjust the hopup to full tilt. Even after that, BB's still jam, only to finally roll out of the barrel when the gun is lowered. Typically, after cleaning the hopup the gun will fire great for 5 or 6 shots, and then it begins to jam. Sometimes, BB's jam for a shot or two, and then (for example) on the third trigger pull three BB's are fired at the target. I've also noticed that the green gas I'm using seems to be very "wet"; it has a ton of silicone. Could this potentially be part of my problem?

 

This isn't the OB version of the gun, but I'm beginning to think that purchasing a OB conversion kit would help correct the issue, as well increase my accuracy among other things. Do you guys believe this to be correct? Also, if I decided to run CO2 after purchasing the OB kit, do I just need CO2 mags to do so, or are other parts required? Thanks for any help!

[jkpics]

Yes, part 117 and the whole hopup design in the CB model is *suitcase*, get a OB kit and you will not regret it.

[kojak]

The OB kit replaces pretty much every moving part plus everything that contacts the BBs. Not saying you won't have any issues, but if you do they will be new issues.

[NonEx]

I would second the above. OB is the way to go.

[kullwarrior]

The OB kit replaces pretty much every moving part plus everything that contacts the BBs. Not saying you won't have any issues, but if you do they will be new issues.

 

To answer for any potential people asking what issue does Open-Chamber have

 

WE AWSS M4 known issue

->Ineffective Hop-up

->Feeding issue

->Firing Mechanism breaking (firing pin assembly, valve locker, hammer, trigger, disconnector)

 

WE M4 Open Chamber

->Nozzle head breaking (When bb misfeed)

->Bolt Carrier wearing out (from using steel trigger or enhanced recoil kit)

->Firing mechanism breaking

 

I would say WE Open Chamber is definitely better than AWSS, however the issue of nozzle breaking is the biggest concern, currently there's no fix than avoid using forward assist when you can't verify if the bb is misfeeding.

 

For those people really want to get RA-Tech Trigger set...

DON'T, unless you are getting the steel carrier as well.

I cycle my M4 about 150 times totday, the crater from the steel hammer is already approximately 1-1.25mm deep. There are reports of steel hammer hitting pot metal carrier to the point of making a hole through to the blow back unit.

 

If you are installing the RA-Tech M4 Steel Carrier, at bare minimum you need to mod the bolt catch and bolt carrier to make it work.

1) The bolt catch point where it engage the carrier needs to be shave down approximately 0.5mm from the top.

2) The part of bolt carrier where the cocking of the hammer takes place needs to be further rounded to have a smoother cycling (otherwise it's near impossible to cycle the gun when the hammer is dropped)

 

After 10k rounds of RA-Tech Trigger Set (Hammer, Disconnector, Trigger, Firing Pin Assembly, and Valve Lock) in WE G39E using stock bolt carrier

-The Firing pin is severely sanded to the point it doesn't completely open the magazine valve when it strikes. This result in "stuttering" full auto where the cycling has a irregular time between shots. The assembly end overall is fine but it has dent where the hammer strikes it.

-The Hammer is dented (less than 1/4mm) by the firing pin assembly, currently beside looks it doesn't do anything.

-The Valve lock has the sharp end sanded off from the firing pin, but it does not affect its functionality.

-Beside from the part where your finger contacts the trigger, it looks brand new with no damage,

-disconnector loss a bit of parkerizing where it contacts the hammer, but otherwise new

 

Final thoughts, The Carrier is showing lots of wear from using steel firing mechanism. Aside from the Firing pin using steel that is too soft I consider it a good investment if you are getting the steel carrier as well.

[ODA15]

Thanks for the help jkpics, kojak, NonEx, and kullwarrior, I've got an OB kit on order now.

 

 

Regarding RA-Tech stuff, it seems there's a couple different thoughts. Is the general consensus that I should stick with the OEM parts for now, and only "upgrade" when the factory parts fail? I've only ran about 300 BB's through the gun, and the internals seem to be okay so far (there's some very slight visible wear, but nothing's pitted, worn or dented yet). The OB kit's trigger assembly has (some) steel parts, right? Does anyone know at what point the sears, hammer, firing pin and valve locker in that assembly begin to fail?

[NonEx]

After reading all the comments and info, I would put it like this;

 

Keep your original internal parts for as long as possible. When they wear out, look for replacement parts for the original parts, ie. from AirsoftBuddy. If you cannot get original parts replacements, look into getting the "upgrade" / RA-Tech parts.

 

It's a damn shame, but it makes sense, pot metal in some spots vs. steel in some places = somethings gotta give...

[jkpics]

To test for worn out trigger parts, first do a function test,

 

Is the safety working?

Is semi working?

Is FA working?

Is the reset nice and crisp?

 

Then there is the visuel inspection, break open the gun, and press the hammer down while looking at the firing pin, the hammer will reset and with a little more pushing down the fireing pin will pop back in, when the parts gets worn the distence betwin the reset and the fireing pin pop will be further and further a way from each other, until running the charging handel will rest the hammer but not the firing pin.

 

That covers wear, if stuff breaks normaly you just get FA on semi.

 

RAT makes some ###### but there trigger set is great, the reset with steel parts is nice.

[ODA15]

NonEx, jkpics, thanks again for the help, I really do appreciate it.

[NonEx]

Just gotta say, I am EXTREMELY pleased with my WE M4 CQBR OB CO2 kit... I mean, I had the WE PDW KAC OB and the WE G39C, and the M4 is by far my favorite... MAGPUL:ed it and it's just a beauty;

 

 

Sorry for the semi-*suitcasey* pic, quick snap with flash. I took the silencer off and put the flashhider back on, makes it look more badass and aggressive.

 

Also, did some target shooting today, and it managed WAAAAYYY better than the constantly overhopping G39 and the semi-accurate PDW. This is 4 magazines (28rds each) at 8m/24ft, crouching and controlled semi-auto fire (where the yellow was is 1", 2.54cm, the black is 2" or 5cm.);

 

 

That is with factory hop setting and 0.25g JBU BBs. Talk about consistent and zeroed in, wooo-haaawh! Lovin it!

 

Also the tip with adjusting the front sight post with a pin punch and pliers worked flawlessly, thanks!

 

I get 50 shots per 12g CO2 capsule on controlled semi auto-fire. On full auto it manages one full magazine of 28 rounds.

 

:-D So darn pleased with this purchase!

Edited September 18, 2011 by NonEx

[ODA15]

I installed and tested my open bolt kit today, and I have to echo NonEx's statement about the gun being consistent and zero'd in. I haven't had a chance to test at a distance, but close range accuracy is great with my biggest (worst) grouping being .75" at 5m. It doesn't seem to be a gas hog either, as I could consistently get 2 magazines worth of firing per fill on green gas.

 

However, I did have a problem. After installing the new bolt/hopup/barrel/trigger pack/bolt catch-release and lubing the entire system, the bolt would only move back about half of it's original travel when the charging handle was pulled. I could and did push the bolt back completely by forcing it with my finger via the "newly opened" chamber. After that, I could rack the charging handle and it would function fine about 19 out of 20 times.

 

I put 60 rounds through it and there was noticeable wear on the bottom of the bolt carrier. But, after cleaning and re-lubing, the wear seems to have "leveled off" so to speak. It's not getting any worse after another 210 rounds.

 

Oh, and the retrofitting kits for the magazines are a pain in the *albatross* to install. I spent a good 20 minutes *fruitcage* around with the spring. Does anyone have a good way to reinstall those?

[NonEx]

Yes. I figured out how to handle the springs.

 

Insert the follower at the top. Screw on the spring cover with the bottom screw only. Keeping pressure about halfway down on the cover, slide the spring into position. Then, using a small tool (small enough the get in the crack of the magazine shell and the spring cover), push/pull (by putting the tool in the crack and pulling/pushing down in-between the spring coils) the spring down towards the bottom, and keeping pressure on it with your left hand fingers, release the tool and pull down the last half, boom, it's in. Keep pressure on the spring cover and screw in the top screw, then the middle screw, and then you can do the others without problems.

Edited September 22, 2011 by NonEx

[ODA15]

Yes. I figured out how to handle the springs....

 

Good idea about leaving the spring partly cover on! I did that and it worked perfectly. Thanks!

[mnmc10]

removing the old cb mag kits

 

remove the screw on top, remove the mag lip then pull the follower out from the top, a small wiggle will let it out. the spring might shoot out so watch out for it.

 

putting in the new kits

 

remove one screw from the spring cover the top one only. with a small tool pull the spring down lift the cover then slide the new follower in. the cover is flexible and wont break even if you bend it up so no worries. by removing only one screw on the spring cover you dont have to deal with the spring trying to shoot out from the side. i can convert a mag in less than 1 min.

[NonEx]

I just bought an WE M4 open bolt kit to keep for spares, contains pretty much all the vital parts for an M4 OB gun, 80 USD;

 

* Complete metal bolt with nozzle

* Complete trigger box set

* Bolt stop

* Magazine conversion kit

* Complete inner barrel assembly

* Dust cover

 

The bolt with nozzle, bolt stop and trigger box (complete firing assembly) being the most important ones. Just a tip for anyone else that can't get original replacement parts seperatly and don't wanna go the RA Tech route.

Edited September 24, 2011 by NonEx

[jkpics]

removing the old cb mag kits

 

remove the screw on top, remove the mag lip then pull the follower out from the top, a small wiggle will let it out. the spring might shoot out so watch out for it.

 

putting in the new kits

 

remove one screw from the spring cover the top one only. with a small tool pull the spring down lift the cover then slide the new follower in. the cover is flexible and wont break even if you bend it up so no worries. by removing only one screw on the spring cover you dont have to deal with the spring trying to shoot out from the side. i can convert a mag in less than 1 min.

 

 

I have done about 40 mags, and here is the fastest way I have found.

 

1. clean the OB mag top, some have molding flashes that will make them har to fit.

2. shell off, bolt release parts off

3. top screw to remove feeder libs, use something to hold back the spring.

4. keep holding back the spring and drop the new feeder libs in, screw them down.

5. remove the 2 top most screws from the spring cover

6. pull back the spring and drop in the follower.

7. assemble the rest of the mag.

 

The only hard part is keeping the damn spring from flying off, and making sure the OB feeder libs fit right.

[ODA15]

Thanks for the help regarding the magazines everyone.

 

Has anyone had the problem with the OB hopup turning itself "off"?

 

I've put about a thousand rounds through the gun, and the grub screw for the hopup is loosening itself now. I'll reset the hopup, fire 90 to 120 rounds, and then BB's roll out of the barrel because the hopup is "off" and the grub screw is almost completely backed out. I'm thinking it's because of the recoil but I'm not sure.

 

I'm going to put a *very* small amount of blue Loctite on the screw and see if it helps at all.

[mnmc10]

just replace the cut up oring which holds the screw in place. i suspect oil got to it and is starting to lose its "plumpness"

[NonEx]

Aherm, updated photo of my setup;

 

 

 

Also here is my final concept pics for the configurations;

 

 

 

I don't really like the looks of the MVG grip, but damn it impoves the overall grip and control of the gun. As oposed to my thoughts on the AFG, looks great, but I have a hard time gripping it properly. Good thing I will be able to run both configs when I get all my parts

 

Still loving this gun!

 

Album link; https://picasaweb.google.com/117328876138007382074/NonExWEColtM4CQBRCO2MAGPULCustomGBBR2011?authuser=0&authkey=Gv1sRgCOuzx9nJiKa8VQ&feat=directlink

Edited October 2, 2011 by NonEx

[neilgoth1974]

Quick question guys, at what part does gas vent at the charging handle? Does it vent more on the top or bottom part? Reason why I ask is I'll be modding the charging handle a bit with a small channel to redirect the gas away. Looking at the wiki site the mod is on the bottom wheras on the real PRI ga buster handle the deeper channel is on top. Thanks in advance for the inputs guys.

 

P.S.

Any preventive measures on how to get rid of surface rust? It's quite humid here in the Philippines and some parts are already showing signs of surface rust.

[Grindstone]

Polish and oil. WD40 is great for rust removal. Gun oil should help preseve it.

[neilgoth1974]

^ thanks for the tip Grindstone. How do you polish it? Is it the same as wiping it down with a clean cloth or do you have to use something specific? I have no access to gun oil locally. All I have now is silicon shock oil. The WD40 I have, will try that soon.

Edited October 6, 2011 by neilgoth1974

[ollie_ty]

Make sure you spray the WD40 onto a rag then wipe, instead of spraying it all over the place. WD40s favourite meal is plastic/rubber.

[neilgoth1974]

Thanks ollie_ty. Got it, will do some cleaning when I get home from work