Loose Body Pins.

[Cr0-Magnon]

Can you glue these in or something? Annoyingly this pin keeps making its way out. Today it fell out completely.

[Hatchet]

Not sure properly gluing them in would be a great idea if you ever want to take the gearbox out again, but *maybe* some sort of threadlock might hold it sufficiently.

 

Sometimes they get held in by general tension, but I've also had ones that are just slack and seem to want to vanish on their own. Could either consider buying a new one (working on the assumption that yours might be a bit worn, or mildly thin) or take the cheaper option of just putting a tiny square of gorilla tape over the top of it on each side of the receiver so it can't fall out.

[Guest]

I’d hammer one end very slightly, mushrooming the tip, and use a punch to wedge it in place.

Remember which side you mushroomed though, or it will cause damage next time you take it out 

[Asomodai]

I wrap them up with something like PTFE Tape. Enough to bunch the tape up when you slam the pin in, so there is enough pressure to stop it from falling out. My old Ares OTTO Repa's pins were very loose and this solved it. 

 

[Adolf Hamster]

Usually that pin should be under load when the gearbox is in position.

 

Both the rear bolt for the stock tube, and the screws in the grip will pull the gearbox back against the pin you have pictured and the rear body pin.

 

It might be the grip isn't giving the proper tension?

[Lozart]

One end should be knurled, the holes in the receiver are different sizes so the knurled end sits in the slightly larger hole. If the hole has rounded out or if the knurling has worn off (or was just shit in the first place) you can get replacement ones that have deeper knurling to take up the slack. Guarder do them I think.

[Cr0-Magnon]

Forgot to follow-up on this, thanks for the replies. The Novritsch team suggested screw glue and it seems to be doing the job so far.