KWA M4 CQBR - Problem Opening Upper

[lowflyjet]

Has anyone had problems opening the receiver on a KWA M4? I can't take apart the receiver even after I remove both the front and rear pins. I can get the rear part of the upper receiver lose and partly opened, but then it jams. Front part of the receiver barely budges.

Any help would be appreciated.

[safx]

Is the charging handle catching on mechbox top tabs?

Most charging handles have to be fully extended while
you pull the upper forward, and then lift the handle up
a bit to shimmy over the bumps on the top of the box.

[LyquidFyre]

You'll only need to remove the rear pin. The KWA M4 receivers are VERY snug , just keep applying pressure when opening.

[m102404]

Let me know if you find anything particular...but I had the same issues on a couple as well that came across the workbench.

Both on the disassembly and reassembly...felt like something was out of place or blocking it from closing up. Couldn't find the source of the problem...but I didn't really go looking for it either.

Safx's disassembly works for split mechboxes (like CA/Dboys). The KWA M4's are very much like TM M4A1's...they "break" open. But for the life of me I couldn't get it to "break"....so I ended up removing both front and back pins to disassemble.

+1 that they're snug builds!

[safx]

..

[safx]

What choo talkin' bout Willis?

The ICS and Systema PTW are the
only split mech's I know of that can
break open easily... and the upper
receiver does not pull away from the
upper mechbox, they slide out of the
tight receiver cavity.

I don't know if the KWA is able to
break ( push the upper receiver up
with the front pin installed, but all
the M4's I made in the past: CA, G&P
and Systema had thick mechboxes
so the upper had to slide into place.
TM stock abs ones barely rise over
the mech's and it's only because the
plastic can flex, and crack.

[LyquidFyre]

I can confirm that KWA's M4 variants will "break" open with only the rear pin removed and the front pin left to swivel.

Worked on both my KWA M4 and my buddy's M4. I found it strange though that when I put the fire select to Semi it makes it easier to crack open. Technically there shouldn't be any reason for this at all as the selector should not interfere with the movement of the upper receiver tabs. Perhaps it's a psyhosematic reaction.

When closing them, definitely use caution not to pinch/break/bend the upper receiver tabs. Eventhough they're metal they could accidentally slip outside of the lower receiver and get broken off.

[safx]

Ahh now I see what Tyson meant.
Coolio, thanks for the info LF. I plan
to get one of these in the near future.

Broken tabs do suck though, I guess
it's a trade off to access the mech
easier.

[m102404]

I said that it's very much like a TM...

The upper has tabs like a metal hurricane body and a TM plastic body...but the mech doesn't get installed/slid into the upper and then placed into the lower like with a hurricane body...

There is enough clearance for the upper to "tip-onto"/"drop" onto the mechbox as it is installed/pinned/screwed-into the lower.

The upper does not have "lips/pins"/edges/etc...at the top rear to catch into the lower (i.e. to lock the upper into the lower like a CA or Dboys body).

I'm sure that you're familiar with the 2 piece TM hopup design...similar to a TM M4, picture the plastic "plate" in the lower that the lower hopup unit and the front-wired-wire guide screw into...now picture that in metal and you have a KWA M4 lower...

It is odd...it's basically a metal "TM Plastic Body"...and very nicely built. There is a little flex...not plastic body flex-like...but there's a bit. There's enough clearance to get it to close up just like a TM M4...that's how I closed up the last one last week...I wouldn't go PTW-slamming ape sh*t on it...especially since it's not mine!

I have some pics that I did for a review...but I've just been too busy to post them here....

[m102404]

Safx...the KWA M4 is an extremely good build...for the cost of them, I'm not sure if I'd build myself another from scratch or just get one of them and go from there.

Shimming needs very minor tightening up, nozzles could stand swapping out to an airseal unit. I don't like the non-ported aluminum piston head.

No comment yet about their upper hopup and barrel quality...

[Shirley]

YouTube - maintaining kwa m4 ris

[safx]

Originally Posted by m102404

Safx...the KWA M4 is an extremely good build...for the cost of them, I'm not sure if I'd build myself another from scratch or just get one of them and go from there.

Shimming needs very minor tightening up, nozzles could stand swapping out to an airseal unit. I don't like the non-ported aluminum piston head.

No comment yet about their upper hopup and barrel quality...

Thanks bud, all is clear to me now

Yah, hence why I sold off my last ICS.
No point in building a custom gun I
don't use much when I can buy the
KWA shooting 400 and lipo ready, for
the few times I do play outside.

Looking forward to your review Tys.
I read a couple from the US already—
hop sucks, everything else rocks, or
so they said. Some claim the front
on the S-system is a Dboys.

[BORDENSNIPER]

alright, I got an KWA too had same problem..or at least I thought I did...

remove the back pin only. grab the carrying handle with one hand, gran the beginning of the buffer tube with another, pull very hard on the carry handle and the reciever will split.

the KWA are a perfect tight fit, when you cles the gun, make sure you piston is all the way forward or the top reciever notches will damage the piston rails.

cheers.

[LyquidFyre]

Originally Posted by safx

........

Looking forward to your review Tys.
I read a couple from the US already—
hop sucks, everything else rocks, or
so they said. Some claim the front
on the S-system is a Dboys.

Possibly the wrong thread for this but yes the Hop is garbage. The hop up unit itself is mediocre. The bucking is horrid as it has absolutely no return once compressed. The sleeve is very thin and seems to be almost TOO thin for a gun that's shooting 400fps stock. It's held up so far though and I've since replaced the bucking on my M4 and my buddies which greatly increased the consistency from shot to shot.

One other thing I noticed that every new KWA M4 owner should do before fielding is to check the 4 grup screws(hex screws) holding the outer barrel to the upper receiver. Make sure they're snug/tight as they have a tendancy to be a bit loose from the factory. This will manifest itself as barrel wobble.

[m102404]

The KWA S-system front end is so-so...I've never did like the fiber s-system handguard (dboys/KWA/otherwise). The Dboys ones are really horrible...the KWA one is ok...not a ton on flex and I suppose it's pretty stiff. Spoiled by RIS/RAS/Other front ends I guess...LOL

The KWA S-system is just like the KWA M4 in that it "breaks" open like a TM M4. I didn't take the last s-system completely apart...the guy had a game to make that weekend.

The outer barrel on the KWA S-System is worth it just in itself...it's like a frick'n solid bar of metal...don't like the handguard, but the outer barrel is nice.