Technical information

Practical A.E.G Upgrade 2006

What causes double feeding?

My gun makes an unwinding noise after full auto firing. What’s wrong?

Double feeding refers to the feeding of two (or more) BBs at once. Double

feeding may result in both BBs breaking or serious jamming in the barrel. Even

if the BBs do not break, their range and accuracy may be greatly reduced.

Double feeding may occur when the feeding mechanism is over lubricated or

when the nozzle is seriously deformed. Based on our experience, a spring that is

too soft can also lead to double feeding. Try installing an ACX stock spring into a

TM and you will know what we mean.

Some people complained that by not following the “one o’clock rule” the

resulting gear timing problem can introduce double feeding as well. Please refer

to our section on the one o’clock gear timing issue – as long as you follow our

recommendations this problem should never occur.

An "unwinding" noise after you fire is a symptom of either a malfunctioning

anti-reversal latch OR a weak anti-reversal latch spring. When the latch is

deformed or when the spring is too weak to support the latch, it fails to grab onto

the bevel gear. Your gun can shoot without a working anti-reversal

mechanism, but at the risk of breaking the teeth of the gears. Based on

our experience, you should replace the spring per every 30000 shots. You don't

need to replace the latch until after around 50000 shots (if you have an insane

ROF, there may be a need to replace the latch sooner).