Extra Donut O-ring left over on G36

[sandman]

After my first attempt at breaking down an Echo 1/JG G36 to replace a spring I had a fairly thick black O-ring left over. It's OD is just a bit larger than a 6mm BB and the wall is about 2mm thick. A 6mm BB will not pass through it

Any one whose broken thier G36 down a few times know off hand where this O-ring is supposed to go. I did a check in the exploded diagram for the G36 but can't see it in there.

A wiser man would have taken some pictures during the breakdown but clearly I'm not that wise.

EDIT: Here's a pic with a 6mm BB for size reference and a few other leftovers ie 2 ring washers and a square rubber piece with a circular hole in the middle.

[Kos-Mos]

I don't know why you would have removed that, but I can only see it fit inside the loading nozzle. Most upgrades/aftermarket nozzles have that o-ring to improve air seal between it and the cylinder head.

That is the only place that kind of o-ring is used in a G36

*wait... 2mm is way too thick... No clue. It is probably not from a G36 then.*

**check on the body pins. I have a set that have that kind of o-ring to "lock" them in**

[sandman]

Originally Posted by Kos-Mos

I don't know why you would have removed that...

That one's easy... curiousity and stupidity. Not necessarily in that order.

EDIT: Pic added to original message...

[Spawn28]

pretty sure those push rings are for mechbox screws and as for the o-ring i have no idea sorry