G&G firing problem

[Ars1191]

Hi

I own two g&g aegs one is a scar (spring downgrade on purchase, g&p 120 motor fitted) the other cm16 raider (modded to the hilt, its my project platform) they are both suffering from the same problem. On occasion a rd will leave the barrel a something that is much less than its proper velocity a bb will pretty much just fall out the end of the barrel and I can't work out why? Both guns have a 6.03 barrel, the hops are set ok(no sailing/overhop), one has a standard g&g bucking the other a systema, I'm using the good 120 magpul p mags and t mags. I've tested the nozzle air seal and on both guns the air seal is good no leaks.

I thought it might be the mags causing some kind of feeding issue so I stripped a couple of them but can find nothing untoward.

It has happened with a variety of brands of bb, most recently ics bbs are these known to cause issues?

Any thought, help and suggestions will be greatly appreciated as I'm stumped

[Zyras]

Re: G&G firing problem

This is a long shot, but my G&G Sig 552 had pretty much the same problem...

On the base of the pistol grip is a small grub screw, this is for adjusting the motor height. Mine was wrong from brand new, took a while to figure it out.

Just try a quarter to a half turn either way and see if it helps, if not, nothing lost.

[Stealthkiller]

Re: G&G firing problem

Have you tried cleaning the barrels recently ?

[highoctane880]

Re: G&G firing problem

I would definitely try different magazines as I have had this problem, along with double feeding occur when using my old JG mag in my G3 while the TM ones work fine. Adjusting motor height shouldn't really affect feeding but you can still try it. Do you get this issue in both semi and full auto or just one of those?

[Ars1191]

Re: G&G firing problem

Mainly semi, but it does happen in both. I am kinda leaning towards a pmag issue as I can't recall it happening with a g&g hi cap. Typically though it only happens a usually a critical moment in a game I haven't been able to replicate the issue at home.

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Yes both barrels are cleaned and lubed (couple of drops of silcone oil) but not over lubed regularly

[emergencychimp]

Re: G&G firing problem

Can't help, but I have exactly the same problem, switched barrels, hop bucking and it was still an issue. I have reseated the hop and still getting the same thing. I would be very interested to hear how to fix this.

[Stealthkiller]

Re: G&G firing problem

Are these gen 1 or gen 2 guns ? The gen 2 are known for over cycling on higher powered battery's . This can cause double feeds etc .
I had this on a gen 1 a while back and it was solved by fitting a sector clip .
I have also had misfeeds / double feeds on pmags always on last few bbs in a mag . I stretched the spring and it solves it for a while .

[emergencychimp]

Re: G&G firing problem

mine is a combat machine, cqw rush. i tend to find its normally with a fresh mag, but not always.

[Stealthkiller]

Re: G&G firing problem

Mids or highcaps causing the trouble? Could try the oldest trick and put a bit of self adhesive Velcro in the magwell to stop any magazine movement Varies gun to gun if its front or rear you need to place it .A bit of cardboard can be wedged in as a tempary fix , and enables you to find which way to pack it . and later fix the velcro , Also look at the nozzle to make sure the mag insertion has not cracked , damaged or chipped it . If its rough edged a very fine emery paper will smooth it out .

[emergencychimp]

Re: G&G firing problem

mids, pmags. Done the velcro thing already and that makes it feed, its the odd under powered shots that is the trouble


Will check it out and have a look.

[Ars1191]

Re: G&G firing problem

Thanks for your input stealth killer. My scar with its down graded spring and up graded motor does over spin a little on full auto only. I could do with putting a stronger spring in and I might aswell get a delay clip at the same time. So I'll try that

[sj_asc]

Re: G&G firing problem

Check the following;

*Hop bucking lip isn't damaged.
*Chamber c-clip (locks the inner barrel in place)
*That the chamber is tightly and freely spring against the front of the gearbox. Some are locked down, but if it's sprung then ensure it returns smoothly and with a lot of force when seated in the upper/front end as shock transferred from the front end of the GB can move the chamber forwards an if it doesn't return consistently as it should then you will have catastrophic seal issues.
*Remember also that the receiver is two halves and that the barrel chamber assembly is seated in the upper, the gearbox is secured to the lower, if there is slight play between the two this will affect chamber alignment with the front end of the GB/airseal nozzle.

Also worth ruling out is Tappet/Nozzle operation.
Unlikely cases can see the Sector gear interfere with the tappets return, but we will rule this out as unlikely, particularly if it's functioned fine without modification from stock.
*Tappet return, with the tappet at rest/nozzle fully forwards try pushing down on the nozzle all the way and see if it returns quickly and smoothly? If contaminants/dirt have got on the guide rails and or the cylinder head nozzle then it would simply need cleaning and re-lubricating. Worst case would be if the tappet has warped, though this is unlikely.
*If you have the gearbox apart it's also worth checking that there isn't anything interfering with the tappets resting position, particularly at the front end as there is room for crap to get in there and seat it's self in front of the tappet.
*Actual feeding issues would more likely point to tappet wear or Nozzle damage and points mentioned above, but in the case of failed air seal, the problem wouldn't simplify be rectified by a tappet delayer.

[highoctane880]

Re: G&G firing problem

Do you have g&p m120s (the high speed one right?) in each gun and what batteries are you using? As stealthkiller has mentioned overspin is a probable factor as, in my experience high speed motors with bigger batteries tend to cause overspin if you leave everything else stock and even more-so with faster gear ratios. It would be worth trying a different motor / battery or both just to make sure. Take the gearbox out and see whether the nozzle moves the same amount every time you pull the trigger. In any case it seems to me that your problem is most likely either the nozzle is not moving far forwards enough each time to create a proper seal (due to overspin) or the magazine spring is too weak to load the bbs into the chamber in time to keep up with the nozzle. Make sure to follow through with everything sniperjesus has said as they are all critical factors that will cause all sorts of feeding problems if not checked.

[Ars1191]

Re: G&G firing problem

The scar has g&p 120 on a big and I mean big 7.4 high discharge lipo. The spring is downgraded I know that but there's so room in my fps to uprate the spring, I'm gonna try a m110 spring see if the improves things

The cm m4 has a lonex a2 (high torque) 11.1 20c discharge lipo. About m120- m130 (not sure 100% bit of a guess) (what ever the blowback cm m4 is shipped with. Ab MOSFET, 13:1 shs gears, 16awg wiring, short stroked by 3 teeth. Lonex cylinder to disable blowback. But it's only hitting 300fps so I could up the spring on that too might try like a m140 in there.

The problem is definitely much worse on the scar but I don't know how overspin causes the symptoms unless its not just over spinning its also pre engaging.

Massive thanks to everyone who's chipped in so far. I'm gonna get my scar apart this week change the spring, give it a clean and relube make sure everything especially the tappet plate and nozzle are moving freely

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Highoctane. I've just reread your post, I think I get it now, overspinning causes the nozzle to be pulled back out of the hop chamber dramatically reducing air seal, correct?

A stronger spring will cut down excess inertia in the motor reducing/eliminating overspin, correct?

Another method I've read a involving add material to the sector gear or cutoff lever so the cutoff lever acts quicker/earlier, is there a tutorial out there for this preferably with photos?

[Stealthkiller]

Re: G&G firing problem

That fps seems very low for a gun running a spring that powerfull 300fps on an m120 spring points to bad compression or an airleak somewhere . Also on a setup that fast have you corrected angle of engagement . The Lonex motor is a very powerfull motor . And will show up the slightest kink in a setup .
To start with try running the Lonex on a 7.4 to see if it feeds better . If not go back to basics and see where the loss of fps is coming from .