[Flatlander]

Your earlier posts make it sound like your tappet plate isn't moving all the way forward; can you confirm that the tappet plate spring was installed?

- After reassembling the mechbox, push the nozzle backwards and see that it springs back forward and isn't jamming. Sometimes on my m4 - depending where the gears are in the cycle - it won't let me push the nozzle in manually but always will after I've closed the mechbox and the tappet cam is at the 1 o'clock position.

- Check to see the hopup/rubber is all installed properly.

The only time I've seen double feeding is with guns where they have vitually no hopup on - adjust it properly and it blocks the other BB's from following up into the chamber. A good rubber you will need to slightly push the BB into it - good check before you install one.

Sounds like you understand how things work (ie. no gear timing, how BB's actually feed etc).