WE M4 Cycling Issue.

[ssrc30]

I got my M4 from Velocity, after waiting 2 months for parts to replace a leaky magazine, I finally ordered the Madbull valves from airsoftparts.ca.

I got the gun working again, but the problem is it doesn't cycle properly. It shoots, but the bolt locks in the far back position after every shot. It does this in semi and full auto, also with the magazine lock switch both turned on and off. I have disassembled the gun and nothing seems to be out of the ordinary, no broken or obviously worn parts are visible.

Any ideas what might be going on here?

I must also say that in order to keep the gun firing without the bolt locking, I have to hold the bolt catch down.

[pugs144]

The bolt locks back with a round in the mag?

[ssrc30]

Originally Posted by pugs144

The bolt locks back with a round in the mag?

It sure does. Even if I have it in dry fire mode, it locks back after every shot. Doesn't matter if it's in semi or auto.

[Ballcancer]

Did you take the bolt stop out when you pulled it apart? If so you may have forgot to put the spring back in... Take the bolt stop out and see if there is a spring in there ... May be the issue or the the bolt stop part in the msg is broken ... Or jammed

[ssrc30]

Originally Posted by Ballcancer

Did you take the bolt stop out when you pulled it apart? If so you may have forgot to put the spring back in... Take the bolt stop out and see if there is a spring in there ... May be the issue or the the bolt stop part in the msg is broken ... Or jammed

No, I never have taken the bolt stop out of the gun. Is there a chance the factory may not have installed it properly?

[Ballcancer]

Could be worth a check... Open the upper half of the gun and push the bottom of the bolt stop in like when the bolt locks back and let go it should pop back out if it doesn't then that's your problem. Also is the bolt stop function on the mag working properly? Like when you set the mag to dry fire does the little tab go down?

[ssrc30]

Originally Posted by Ballcancer

Could be worth a check... Open the upper half of the gun and push the bottom of the bolt stop in like when the bolt locks back and let go it should pop back out if it doesn't then that's your problem. Also is the bolt stop function on the mag working properly? Like when you set the mag to dry fire does the little tab go down?

The bolt stop function on the mag works fine and I just checked the bolt stop and it springs back just fine. I am confused as to what the problem could be here because there doesn't actually seem to be anything wrong with any of the parts lol...

[shelcoof]

I Just bought myself a WE PDW and 5 "New" Mags on here in the classifieds. I'm having the exact same problem as you with the 5 new magazines I bought here in this thread.

http://www.airsoftcanada.com/showthr...M4%2FPTW+Rifle.

PDW is working great with the stock PDW Mags. However, all 5 M4 Mags that I just got in today aren't working properly.

Here is a run down of what the problem is.

PDW Mag included with my purchase on another thread works perfectly.

- On Dry firing mode when I click on the dry firing switch on the mag. It dry fires properly without having bolt lock back.

- PDW Mag when loaded with BBS empty properly and when empty the Bolt Locks back properly.

- Both Semi and Full Auto work perfectly on Dry firing and loaded with BBS.

- PDW Mag fits into PDW easily.

M4 Mags Tan problems.

- Loaded with BBS, the the bolt locks back all the time. I can get 1 shot off and I'll have to reset the bolt myself.

- Empty with dry firing switch on, the bolt locks back all the time and I will have to reset the bolt myself.

- Loading a magazine into the PDW with M4 Tan mag. I'll have to push a little harder for it to lock into place

- Semi/Full Auto on both Dry Firing and Loaded with BBS Bolt always locks up and I'll have to reset the bolt myself.

It would be great to figure out what the problem is. So far I'm guessing its the M4 Magazines.

I've contacted the seller regarding this issue but have not heard back yet.

[shelcoof]

Alright so I took a closer look at the problem and I noticed the M4 mags are a bit tight and need to be pushed in a bit harder to lock into place. The M4 Magazines does not sit flush into place. With the added space of about 1-2mm sitting higher than normal. This causes the bolt stop (Part 67) to push up halfway about 1-2mm causing every shot to lock the bolt.

I've done this comparison with and without the upper receiver. Without the upper receiver I can get the M4 Magazine to sit flush but without I always have to give it that extra 1-2mm nudge to lock into place.

Gun shoots fine with original PDW magazine that sits flush in the magwell. I'm assuming the Mags are defective?

[Fuzzy]

I had the bolt locking back problem when I installed a replacement bolt catch on my CQBR open bolt. When I compared to the original I noticed that the flat part that contacts the mag had been grinded down on the original. After demelling the new bolt catch it now functions normally. I also had to dremel the elbow/shoulder part of the bolt catch to round it out a bit but that may not apply to the pdw.

[shelcoof]

Originally Posted by Fuzzy

I had the bolt locking back problem when I installed a replacement bolt catch on my CQBR open bolt. When I compared to the original I noticed that the flat part that contacts the mag had been grinded down on the original. After demelling the new bolt catch it now functions normally. I also had to dremel the elbow/shoulder part of the bolt catch to round it out a bit but that may not apply to the pdw.

Was this the only way to fix the issue? I don't want to have to modify my gun just because I'm unsure if it is my gun or the magazine. Gun is working perfectly already with PDW Magazines so I don't want to risk it.

Magazines are much easier and cheaper to replace while Gun... not so cheap and easy.

I've tried to modify the Magazine instead by sanding down the area where the dry fire switch is but still not working right.

I appreciate the reply
Thanks a bunch

[ssrc30]

Ok, I have tried everything. Mags seat well in the mag well, everything is properly in its place, but I still have the problem of the bolt locking back after every shot. Is it possible I may have gotten a faulty unit? Should I maybe try upgrading to OB, or full steel CB internals?

Another game with this gun working like it does just wont do lol

[Ballcancer]

Hmmm thats weird that this issue is happening... My only guess is thay the bolt lock tab is stuck in the "lock" position. THAT! or you may have to do some grinidng the to the part of the bolt catch that contacts with the bolt carrier itself ... Most likley not .... When the you put the mag in dry fire mode does the little tab fall down? If ao i think the tab is jumping and pushing the bolt catch up ... If this is the case try putting in a bit of a stiffer spring maybe? Let me know.

Also from my personal experience ... The OB is no more than a cool factor ... My OB kit causes nothing but problems ... From ROF issues to the bolt catch. Ot working to the bb's not leavin the barrel... My CB kit on the other hand has worked %100 everytime never fails i have had dirt and crap and god knows what else caked in the fire mechanism as well as the BCG and the gun still fired great. And yes upgrading to steel parts is a good idea ... I would let te original parts wear out and then do steel internals ... Word of warning though you may have to do some minor filing to those steel parts to get the gun to fire right ... Just means project time with a dremel

[ssrc30]

Thanks for the tip. The tab seems to be working properly as well in dry fire mode and it sits up fine when I switch the setting on it. I might upgrade the internals over the winter. I run GBBR only so my airsoft season is over here, now is the time to upgrade I guess.

I might try that grinding idea first though.

[Ballcancer]

I would make sure that its 100% bolt catch alone before you do that and if you do only grind the outside of the tab - so if the paddle (the part you push to release the bolt) is facing towards you - then the part that makes contact with the bolt is directly behind it.. I you want to grind off the paddle side of that nub.... but use a file and slowly file down.. do ten or so strokes then put it back in and see what happens and keep doing until it works properly .... also search the dedicated WE AWSS M4 thread... there is tonnes of info on there that may or may not help you.. that and the guys in there really no what they are talking about... I solved all my issues in that thread! Good Luck!