Echo1 M4 issue. Please help!

[sweeper]

Hey everyone. I am in need of some help. I have an Echo 1 m4 stag 15. After cleaning the barrel and hop up, the gun stopped feeding. I tore the gun apart three separate times trying to figure it out. The gun sounds fine, the bbs just don't fire. When i try hand feeding the gun it pushes the bbs back out (through the mag "area"). Im relatively familiar with repairs, but this one has me stumped. There is nothing blocking the barrel or hop up, the mag and battery are fine, the tappet plate and air nozzle appear to be fine (I'm not 100% sure). Ive replaced the hop up bucking, opened up the gearbox and checked everything out. I can't think of anything more to do. I would like to get back into air soft this summer, and I need my gun working.

Any ideas what might by wrong?

I live in olympia, so if anyone lives close I could meet you to look at the gun.

Thanks!

[Applegate__Airsoft]

Hey just hpa that thing

[Payback]

You screwed up your hopup. Most likely the bucking. You either installed it wrong, or it's bad. Check the line up of the hopup and bucking with the assembly out of the gun. Push some bb's into it out of the gun and see if that is the problem. If it's the 2 piece hopup, make sure you got all the parts screwed in correctly on the lower.