WETTI/AWSS - M4/SCAR/HK416 - Technical Summary Thread

[El Cactus Loco]

hey for all you guys out there having trouble with the green gas mags. i originally had only 1/5 mags not leaking. now i have 3/5 with this new trick (the other 2 need parts)
the trick is to put the big square o-ring into the backplate. make sure it is fully seated around the perimeter. then mate it to the mag body and screw down the 4 screws to juuuuust finger tight. then shoot a blast of propane/green gas with lots of silicone in there. my theory is that this blast forces the o-ring to seal between the backplate and body. then screw in all 4 screws about half way and give it another blast of gas. it will leak at both these stages, that is normal. then tighten down the screws HARD. be very careful not to strip the screws or worse the threads in the mag. the mag should now be mostly sealed. if there are any small (hissing) leaks, they should stop after a few fills. fill it up then just leave it to seal. mine did over night. i picked them up this morning, and all 3 fired!
good luck

[Greydingoe]

So, my scar works on full auto but not on semi. I pull back on the cocking lever to load the first BB, pull the trigger, then the trigger stops after the first shot. To get it to shoot again I either have to pull the cocking lever again OR switch it into safety and back to semi. Was wondering what this could be.

[808]

Originally Posted by El Cactus Loco

hey for all you guys out there having trouble with the green gas mags. i originally had only 1/5 mags not leaking. now i have 3/5 with this new trick (the other 2 need parts)
the trick is to put the big square o-ring into the backplate. make sure it is fully seated around the perimeter. then mate it to the mag body and screw down the 4 screws to juuuuust finger tight. then shoot a blast of propane/green gas with lots of silicone in there. my theory is that this blast forces the o-ring to seal between the backplate and body. then screw in all 4 screws about half way and give it another blast of gas. it will leak at both these stages, that is normal. then tighten down the screws HARD. be very careful not to strip the screws or worse the threads in the mag. the mag should now be mostly sealed. if there are any small (hissing) leaks, they should stop after a few fills. fill it up then just leave it to seal. mine did over night. i picked them up this morning, and all 3 fired!
good luck

Tried this method, and I got a leaky GG mag to actually hold some propane. Unfortunately, it wasn't nearly enough to matter - the gas was gone after 10 rounds.

BUT things are looking up. I was thinking about adding a layer of nitro tape to the rectangular o-ring in the rear of the mag. Anyone have any success with that?

[El Cactus Loco]

have faith. some times it took a few tries!

[Thenooblord]

I've never had any real issues, once I left it ungassed for like 2 months and it leaked, so i just took it apart put some oil on the rectangular oring and it was dandy, what are all these issues u guys are having?

[m102404]

I have definitely found that if you let your mags sit for a bit unused...they'll leak when you next fill them. Especially if you leave them sitting empty.

The mags like oily gas. I'll try to give them a extra bit of oil if I'm going to store them away for a bit...but don't always.

I find that "over-oiling" them after they've been sitting sometimes revives them...but I've got 2 that just wouldn't seal again no matter what I did.

I used some silicone sealer and ran a bead before assembling. I took out the fill and knocker valve to assist with drying. I left them to sit for probably a week (just coincidental...busy, busy) before I gassed them up. They hold gas 100% now. But I've used too much sealing material and have to run some cycles of gas through them to blow out extra junk. It works, messy though.

Personally, I'd say...use oil in the gas, store them almost fully gassed, use them frequently.

[BIG]

Hey guys.

after 11 mags or so with CO2, I found some cracks (or mor like small white line) on the lower receiver. When I did my bolt stop modification (see previous posts) I also put in 2 screw to hold the PVC block in place. one on each side. I found out that this screw was acting like a hindge and applying the recoil force downward forcing the corner of the block to "open" the lower receiver. Hence, the small white lines. (I'll post pictures tonight so you guys can understand better). I then decided to fill the bottom of the block with hot glue. Hot glue is like a shock absorber. I shot maybe like 15 more mags and now it seems to be ok. When I have more free time I will add 2 more screws.

Now for mags problems. I have 5 CO2 mags. 3 are working good. 1 is completely new and useless. As soon as I screw the cardridge in it it all empty by the striker valve. The other one is slowly leaking. I tryied to use silicon oil on the orings but it did not helped me. Now I'm hunting for another type of oring. Maybe a softer type to help seat better...

If you guys have any idea or experience please let me know. I'll keep you updated on how my search turn out...

Later

[BIG]

here's the pics.

I have included a picture to show the angle of the brass cylinder.

Are yours at the same slight angle?

[808]

From what I can see, my cylinder is completely parallel to the upper receiver.

As for your mag problem - I primarily use GG mags - can't help you there. The only CO2 mags I have are for testing my aftermarket steel parts, and they don't leak - not yet, anyways.

[BIG]

Thanks 808.

I tried to find a way to adjust the barrel to make it level but it looks like the problem is the part that hold the barrel is not machined correctly. that is why I was thinking it might be angled on purpose.

Do the GG mag and the CO2 mags have the same top valve? (striker valve)

[jamuke]

all of a sudden my scar wont fire?

everything looks good though I'm starting to show pronounced wear on the hammer.

I removed the lower receiver and inserted an empty mag to see if the striker hit the valve and it seemed to.

I gassed the mag some inserted and pulled the trigger and got a little pffft ..I would have expected more.
I put a bb on the flow rubber and fired, and the bb fired up about 5 ft , it doesn't seem to be releasing the right amount of gas

The valve striker shows some wear on the lower portion but how much wear would it take to make the striker useless?

sorry, can't get any pics up

[808]

You may need to take some pics, or disassemble the trigger group to see what the deal is.

As for wear on the striker, I've heard of people using severely worn strikers for a long time, and some people's wouldn't fire anymore with only slight wear.

The striker may be the culprit - but it sounds like there's more going on than just that.

[Shirley]

Originally Posted by jamuke

all of a sudden my scar wont fire?

everything looks good though I'm starting to show pronounced wear on the hammer.

I removed the lower receiver and inserted an empty mag to see if the striker hit the valve and it seemed to.

I gassed the mag some inserted and pulled the trigger and got a little pffft ..I would have expected more.
I put a bb on the flow rubber and fired, and the bb fired up about 5 ft , it doesn't seem to be releasing the right amount of gas

The valve striker shows some wear on the lower portion but how much wear would it take to make the striker useless?

sorry, can't get any pics up

You can't test the gun like that..

Doing that method is like releasing gas out of GBB magazines, and it will cause the rubbers and o-rings to freeze and damage..

Have you let the magazine to cool down?

The valve striker always and soon be worned out.
If it's worned out like a chunk of half missing, you would need to replace it.

[jamuke]

thanks Lanny,

fortunately.. or not in this case the striker doesn't come out far enough
to expel the gas

if I gently pull out the striker ,the assembly it will come flush but when I release it, it pulls back about 1mm from flush

I removed the assembly and saw no broken bits

[Shirley]

Try pulling back the hammer.
Slowly pull it back manually, you should hear 1 click, then the second click.
Then pull the trigger to release the hammer.

If not, then this part may be broken.
Or that you lost the spring for this part.