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

[m102404]

What Gas to Use

Propane vs. "duster" vs. CO2

NOTE: The following info is not solely my own...it's a compilation of the info from various previous posts

In general, the WE platform was designed to run on green gas (i.e. propane). Calls from the public asked for a harder recoiling system...so they built a CO2 mag and made some changes to the nozzle design (i.e. the flanged vs. the bottle neck design). Other than that there aren't any material differences between any of the pre-CO2 and CO2-ready models. That said...the faster/harder recoil speeds of C02 really put a beating on the rifles. Most notably the SCAR's design of a very heavy bolt with plastic parts cannot take sustained wear and tear on CO2.

Out of the box velocities are all over the place...from lows of 340fps on propane to highs of 590fps. It's dependant on the position of the float valve. So you MUST chrony yours to see what it's shooting.

Duster gas will drop the velocities but it's not a guarantee that it'll reliably cycle your rifle...nor does it lubricate anything.

In general...the concensus is to use the gas that results in the most consistent operation....and use an adjustable nozzle system to tune the velocity.



- M4 A1, 363 tightbarrel, Using Xcortech chrono, goldenball BBs, 1st shoot is =520, 2nd =545, 3nd = 575, 4th = 671.9?? Can this happened ? but then back to 520 - 545 fps...I'm using 195psi gas ( guarder black is 150psi )...

- I was using a CO2 magazine and it's firing at 530fps with .2g which seems to be 2 fast to get the bolt catch to catch. The propane mags firing at 430fps with .2g are catching. Guess I'll just have to wait for the npas valve

- The NPAS is the way to reduce the FPS. Also if your Scar has a Steel Nozzle it's rated for C02 if it's brass then it is not.

[MrEvolution]

re: my freezing.

Took my mags, emptied gas. Held open the valve and sprayed some 'liquid wrench' silicone spray into them (a good amount). Let sit a few min then filled some propane into the magazine. Heard a bubbling sound as it mixed with the oil.

Letting it sit overnight and will hopefully try it tomorrow.

[fumoffu]

Need some help.

So I ordered RA TECH WE firing pin base+Valve knocker for the Scar and it seem it doesn't work at all. It seem the WE stock hammer is not catching the valve locker.

So far the gun wouldn't shoot with the mag.
All I can tell after install everything back with the ra-tech parts. The knocker would not pull back and only if I push the hammer down further then it will.


Any ideas to fix?

Cheers,
fumoffu

[m102404]

Not sure what the "valve locker" is...but I'm guessing it's what's called part #66 in an M4 (the part isn't actually numbered in the SCAR).

Also, a detailed description on what/how your rifle is acting is helpful.

How to test that the knocker is working.

1. Remove the magazine
2. Separate the upper from the lower
3. Cock the hammer manually (the knocker should retract from the area in the magwell)
4. Make sure the selector is in semi
5. Pull the trigger, the knocker should be knocked forward
6. Cock the hammer slowly...you should see the knocker retract at a given point when the hammer is moving back.

If it's not doing that, you've got to check that part #66 is installed correctly and that the spring is in place. The legs of the part must ride on the hammer and ride underneath the knocker.

The knocker must have it's spring installed under it..and the tiny little peg that goes in the spring.

The parts should move freely...and not be a tight fit at all. With some of the machined aftermarket parts, you might have to round edges, file, etc...to get it to fit your particular trigger/hammer housing.

You can test all this with the whole trigger unit out of the lower...but becareful that the little spring for part #66 doesn't fly off (piece of tape over it will hold it in position temporarily or just keep your thumb over it).

[m102404]

***NOTE***
In an effort to tidy this thread up I'm going to ask a mod to delete a number of old posts in this thread. Mostly...
- repetitive questions
- back and forth info
- buy and sell stuff
- other items that are covered somewhere else in the thread or that can be consolidated together

* I am reading each and every thread that I'm submitting to be deleted
* I am doing my best to review, interpret and consolidate the info in a post before I submit it
* I will remain impartial...so even info from "dubious" sources is getting a fair chance
* If your post is deleted, please don't take it as a personal affront...this clean up is meant to make all the info more accessible to anyone who reads through this thread.

** if you feel that I've made an error and missed something...by all means speak up.

Please and thanks,

Tys

[MrEvolution]

Originally Posted by MrEvolution

re: my freezing.

Took my mags, emptied gas. Held open the valve and sprayed some 'liquid wrench' silicone spray into them (a good amount). Let sit a few min then filled some propane into the magazine. Heard a bubbling sound as it mixed with the oil.

Letting it sit overnight and will hopefully try it tomorrow.

Update:
NPAS still freezing after 1.5-2 mags, attempted inside.
Have removed bolt and oiled it well, letting it sit out for a bit. Oiled trigger group and valve knocker.

Mags are not locking back as well, may be BAD Lever related. Will remove and see if that's an easy fix.

[Dart]

Alright guys I have made it to page 17 of this and have seen this requested a few times.

I am running the latest gen scar with a Npas nozzle and all co2 mags.

One big worry seems to be the hinge plate. I have had about 30 mags through mine so far and some dry firing. The hinge plate has some scuffing from where the return spring sits on it how ever I have had no cracking. But I think I know why.

While trying to get my bolt catch working *still not working right* I ended up cutting the spring to try and slow down the bolt return. This how every made the gun not cycle right. Sooo I cut a few coils off another spring and added them back onto the guide rod. Infact it has strengthened the return spring and I believe this is what is keeping my plate alive. The fact that the return spring actually sits against the plate compressed just slightly, not allowing it to have a jack hammer effect.

Now other than the bolt catch not working 100% I have had no other issues with the co2 mags. They do leak out of the knocker valve once in a while but a silicone oil bath does solve that.

Draw back to them is you get about a mag and a half out of the powerlett. so either your stuck loading 15-20 rounds for the second go or your throwing away still charge powerletts. On field I load them and fire until dry, off field before game I just throw fresh ones in.

As for oiling the mags the best way I have found is to put a few drops in the expansion chambers *the ports just below the valve* putting oil on the top of the powerlett and screwing it in is not sufficient and causing the mag to leak eventually.

the FPS with my stock valve on co2 was roughly 560fps. I brought that down with the Npas to about 410 *our field limit is 430*. This seems to be a sweet spot for the hop up. Anything slower I was getting horriable dive. Faster I was getting no hop effect and very random shots.


As for cool down on the co2 mags I can get roughly a full mag out in a string how ever I never actually do that on the field... its fine for 3-5 round bursts and bouts of cover fire. I have used them in 17c with absolutely no issues reported. Also as hot as 35c. Mag was to hot to even touch and the fps did jump a bit on the first shot but the rest was nice and steady.

Any other q's about the co2 set up let me know. I have an idea on how to get the bolt catch to work, Just need to get around to it.

Edit: just a tip with the co2 mags they do like to lose the clear oring that the powerlett bumps up against. if this happens go to a paintball store. They usually have tons of orings in stock and should be able to get you up and running again. Also DO NOT SWING THE MAG to get the powerlett out. That is a good way to have the oring go flying with it.

[m102404]

I've deleted about 200 posts so far and will keep going...

That's great feedback on the CO2 front...thank you!

I know a couple of guys who have gone completely over to gas guns and are now looking at CO2 mags for the fall/cooler season.

[MrEvolution]

Originally Posted by MrEvolution

Update:
NPAS still freezing after 1.5-2 mags, attempted inside.
Have removed bolt and oiled it well, letting it sit out for a bit. Oiled trigger group and valve knocker.

Mags are not locking back as well, may be BAD Lever related. Will remove and see if that's an easy fix.

Removed BAD Lever, bolt now locks back on empty mag.

NPAS still freezing. Now pissed off. Any ideas guys?

[m102404]

Sorry Sam...over-eager on purging posts...

Quick summary setup?
- SCAR/M4/PDW
- CO2 or propane
- RAtech's NPAS?
- other mods?

Are you in for Oct 3 FR?

Tys

[spartan4205]

After reading through all the information on the WE GBBR's, and observing some on the field, these GBBR's seem to need a huge amount of maintenance to game successfully. Now I know the GBBR's are suppose to be more 'realistic' but isn't all this extra work to keep the WE's shooting a big pain?

[Dart]

Originally Posted by spartan4205

After reading through all the information on the WE GBBR's, and observing some on the field, these GBBR's seem to need a huge amount of maintenance to game successfully. Now I know the GBBR's are suppose to be more 'realistic' but isn't all this extra work to keep the WE's shooting a big pain?

its a labour of love, like owning a wood boat or an old car. They are simple things to work on. But don't under take it if you just want to go play. Honestly though I have had less probs with my WE scar than my VSR.

I have a TMak47 as a back up and it comes out to every game. I would never buy a GBBR with out owning a AEG.

[SINN]

have you worked on an AEG? Minimal mait required on a GBBR compared to AEG's. AEG's can be a great workhorse but once you get into eletrical trouble..it can be a nightmare. I love the simplicity of a GBBR. Once you take it down, you completely understand the internal workings, where as with an AEG...its all messed haha

[m102404]

Originally Posted by spartan4205

After reading through all the information on the WE GBBR's, and observing some on the field, these GBBR's seem to need a huge amount of maintenance to game successfully. Now I know the GBBR's are suppose to be more 'realistic' but isn't all this extra work to keep the WE's shooting a big pain?

That is a very good observation and fair question.

[*edit* quality working reliable] AEGs are very much..."slap a battery in, fill mags with BBs and you're good to go"...pack it away right after a game...take it out last minute before another...add battery/bbs and go.

GBBRs are not so much. They are essentially a big gas blow back pistol....cycling heavy parts with lots of gas.

For maintenance...they're like a cross between a real rifle and a gas pistol.

Maintenance free...absolutely not. But the maintenance is very straightforward and centered around checking it over and lubing up the gas/moving parts.

Once you've got the lubing figured out...there's not a whole lot to do.

For example...this is ALL I do:
Pregame
- gas/oil mags - load BBs
- run a cleaning rod down the barrel
- tune NPAS to field limits

In Game
- gas/oil mags + BBs

Post game
- wipe down rile (there's rusty steel bits on mine and it always seems to rain)
- gas/oil mags
- once over...looking for torn o-rings/cracks/breaks/loose stuff (i.e. my flashhider almost shook off the last game)
.....takes about 30 min to clean it up and pack it away

So...in the end it's less maintenance than a real rifle (i.e. cleaning/lubing)....but certainly more than an AEG.

Shoot an AEG for a while....then shoot a nicely working GBBR.... it'll ruin you and a lot of guys won't go back.

[Dart]

I agree with that lol. Going to an aeg from my gbbr.... I pulled the trigger and went "really? That's it?"