G&P Gearbox issue

[Wølf]

Not too long ago i bought a G&P m16 but when i chrono'd it the reading were around 410fps, im no stranger to gearbox work so i opened it up and set about shortstroking the piston and sector gear to decrease fps and increase ROF, it was working fine up until lunchtime on its first skirmish but then it stripped the teeth on the piston.

 

I nabbed another piston out of a spare gun i had kicking about but didnt fancy shortstroking it again so i used all the gears as well (TM SG550)

 

So, all the gearbox internals are now standard TM and i bought a new guarder V2 tappet plate as the G&P sector gear has a delay thing on it so the old tappet plate was different.

Ive been using it but ive found it will fire ok on semi auto then for about 5 shots it will drop stupidly short, on full auto all the rounds drop shorter than i can throw, All the hop unit/rubber is in good condition and it fires at around 340fps.

 

Anyways, i got pissed off with it yesterday so i had a look in the magwell and watched the movement of the nozzle as i pulled the trigger on semi, 1 shot leaves the nozzle fully retracted, next shot leaves it fully forward, next shot leaves it half way accross the feed tube hole then the next shot goes back to fully retracted

 

Ive had it all apart again today and all the internals seem to be as they should so im confused, should i have changed the cutoff lever thing as well? Is there something blatantly obvious im missing?

[RR01]

First question would be, why didn't you just get a weaker spring for about £10, rather than mucking about with a perfectly good G&P gearbox?

 

As regards the nozzle problem, obviously something isn't right in the gearbox as the nozzle should return to the front each time it's ready to fire, which is why you are getting no range on auto as the air is escaping out of the side of the hop instead of down the barrel.

 

Your best bet seems to be to find a competent airsoft mechanic and get him to sort it for you.

[Wølf]

First question would be, why didn't you just get a weaker spring for about £10, rather than mucking about with a perfectly good G&P gearbox?

 

Because ive shortstroked many guns in the past without any issue, yes i could have bought a weaker spring but why bother when there are other methods for free, why buy a new one when the old one could still be used?

 

 

Your best bet seems to be to find a competent airsoft mechanic and get him to sort it for you.

 

Is that some sort of a dig? Like ive said im no stranger to AEG internals, ive just never had this issue before.