Help! Double Feeding Problem
 

My AEG double feeds on both semi and full auto. I've checked the hopup, everything is fine. What solutions do I have to fix it?
Thanks

try other brand of mags

I also tried that, didn't help. Should I try using a sector gear delayer chip?

Your hop up unit is having issues, either it cracked or has been positioned wrong. Either way the hop up rubber bucking moves forward enough that two BBs can enter the chamber instead of just one. Give it a good looksee over and see if anything wrong with it. I've fixed a half ozen guns with double feeding issue, all were related to hop up and thing else. I'm looking forward to seeing someone post a different reason from what they've found for this issue. :)

I would agree that the problem lies within the hop up chamber. do you have a two piece or one piece hop up?

It's a 2 piece, anything particular that I should look out for?

What kind of AEG do you have? If its an AUG then it is a common problem.

Try replacing the hop up rubber.

tappet plate could also be warn, seen this happen to my friends CA after about 4 years of use.

FYI, the sector gear delayer would help when you have feeding issues, not double feeding. It just keeps the tappet plate back longer to make sur the magazine's spring pushes a BB all the way up so the nozzle chambers it.

The double feeding still happens when I used another hop up rubber, I think I might just buy a 1 piece metal hop up unit. What brand is good for hop up units, G&P?

Get a systema hop-mech.

if your gun comes with a two piece, you're going to need to modify your lower receiver for the one piece to work.

I have the same issue (double feeding) with my g&g gr16 m4. I use a mad bull ultimate hop-up. With the original green hop up rubber that come with the g&g. The blue one that come with the kit was unable to fit.

The barrel is a prometheus 6.03 500+mm and a full bore up kit in the gear box.

What should I do?

EDIT: gr16

sebdark, if the above recommendations doesn`t work for you, inspect your magazine feed tube and the hop-up bb feed tube. Are they aligned and the mag spring engages/released a bb when fully-seated?
Also check your tappet plate, you could be having issues there.

I removed the hop up madbull and changed it with orignal and it work without any problem (100+ bb fired without problem).

:D

Ok update, right now it feeds properly, but spits 1 extra BB out after every shot, on both semi and full auto. What can explain that?

So right now I got a 1 piece hop up unit made by dream army, however it still double feeds. I tried 3 different buckings and nothin has changed. I'm pretty sure that the hop up unit is fine, so what other explantions can there for this?

The spring that pulls the tappet plate back could be stretched or weaken and causing the double feed. Instead of snapping forward to allow 1 bb to be loaded, it's staying back longer and allowing 2 bbs to be load. Just a theory but look into that.

I replaced the spring with an extra spring lying around, as well as the tappet plate. It still double feeds though, except on only of semi. Sometimes, on semi, it would shoot then a BB would roll out.

Do you hear strange sounds coming out of the gearbox, like the gears would spin reverse? If the anti-reversal latch is broken or the spring is too soft, it might cause the gears to back off, then resetting the tappet plate into the hop up, pushing a BB.

Could that be the only reason? I'm pretty sure my anti-reversal latch is working fine.

you might have an over spin issue. What battery are you using? Spring? Motor (high torque or high speed)?

I am using a 25C 7.4V LiPo, a roughly M100 spring and a stock motor.

the cause of your problem could be that your battery is causing the motor to spin 1.5-2x. So your first shot is normal but the motor continue to spin loading another bb, but it just rolls out of your barrel. Use a lower power battery or get a high torque motor.

Ok, I've been messing around with different combinations of hop up rubbers and nubs to see what they would do to the double feeding. Most of them still make the gun shoot 2 bbs. I think that the bb rolling out was just a fluke.

What kind & brand of mags are you useing.

I seen some hi-cap mags that made the gun double feed do to the hi-cap spring being to strong when wound up all the way.

I am currently using a hicap, made by AIM (I think).

WOW, crazy issue. Over the years I have noticed the following;

- a double feeding issue is usually caused by an incorrectly adjusted hop up OR the nozzel is worn/cracked and needs to be replaced (however, any accumiliation of crap infront of the tappet plate within the mech box will have the same effect).
It is also possible that the wrong type of nozzel/hop up is being used. I have found this issue to be common with many DBoyz and JG AEGs, where in some has switched out (up graded) the nozzel with one that actually snags up on the inside if the hop up (the same can happen it you swap out the hop up unit itself but not the nozzel). This issue is always accompanied by a huge fps loss.....common in the JG G36. If the nozzel is too short, it is not only not sealing with the bucking, but can allow multiple BBs into the hop up which will result in double feeds.
A worn tappet plate usually results in miss/non feed issues (as the nozzel is not being cycled back far enough to clear a BB). But a very badly stretched tappet plate return spring could indeed cause double feeds.

In the case of using high voltage batteries, if the double feed is not consistant, but only occures at the end of the cycle, I may be inclined to believe that it may be an "over spin"issue (only considering that he is using an M100 spring). But again, I can only see this being a problem caused by an improperly set hop up.........the typical issue with LiPo battery users is mis feeds, not double feeds.
*Using an M100 spring may eventually cause your LiPo set up to self destruct. Do some research on pistons getting stripped by LiPo batteries when using low fps springs. Something about the piston not getting back to zero position in time for the next cycle.

- when using any combination of MADBULL barrel or hop up units one must be careful to match the bucking to mate properly. A MADBULL barrel not only has a smaller ID (inner diameter), but also has a smaller OD (outter diameter) than a standard TN (tight, narrow or "tight bore) barrel. When using a MADBULL barrel (regardless of the type of hop up unit) always use a MADBULL hop up bucking, or you'll suffer air seal issues at the hop up.
I am unsure what the issue is with using a MADBULL hop up with other brands of barrels as I never utilize the MADBULL hop up units.

- low quality mags would cause mis feeding, not double feeds....unless they have wicked spring pressure.

SHA DO

I recently drained the battery's power, then charged it for a little bit to simulate lower battery power. What I found was that it feeds flawlessly, so it might be an overspin issue. What can I do to fix this; I'd like to keep running my 7.4V LiPo.

Bump, any updates?