Double feeding

MonkeyGuy

Doing up my old Double Eagle UMP and it's going fairly good. New motor etc... Now it's shooting great, except when it double feeds. Is this a problem with the mag or is there something else that could be wrong? All help appreciated thanks.

evilrobotshane

It can be caused by the mag; particularly the first few BBs, when the spring is very compressed, it can shove extra BBs up in there. Try half-loading a magazine. Also, the hop-up rubber can be stretched - if you remove the barrel, try dropping a BB into the hop-up rubber. It shouldn't fit, it should sit in the mouth of it.

MonkeyGuy

BBs aren't dropping through so that's not the problem but even when it's getting near the end of the mag it's still happening?

Dread-Lock

The UMP mags are known to have too strong a spring in them. Try leaving them loaded overnight to weaken the spring a little. See if that helps.

MonkeyGuy

Will do. It's a bit weird because I don't remember it happening before? And it's virtually impossible to open up the mag so I couldn't investigate. Thanks for the advice.

Dread-Lock

Well when you said your doing up your old UMP, I assumed its been lying around not getting much use (much like my UMP atm ). So the springs could have stiffened up a bit in storage.

And yeah I could never get the UMP mags open myself either.

MonkeyGuy

I must say you have got an unarguable point! It's hard to believe how much can happen even if you keep it stored safely! Ok so make the spring softer and I should be ok? And I was reading some threads around here I reckon I'm going to have to open up the gearbox and oil it properly. Something about oil turning to dust?

MonkeyGuy

Had a go at the gearbox today and it's all lovely and oiled, but I realised that the air nozzle might not have been connected to the spring properly to push it against the hop up? Might this account for the double feeding? Haven't got out to shoot it today and it's too dark now but I'm still dying to know!