So I was reading some of the latest Q&A responses, ( not all sites have theirs up yet), and turned my attention to the LAST round of Q&A--a couple months ago.
An therein I learned something about a figure that had been bothering me.
POC Iron Grenadier, more specifically his "smart gun".
From TRM( bold is mine):
1) Is there an additional swivel arm piece missing from the Iron Grenadier smart gun? The one that comes with Destro doesn't seem to work in its place.
Answer: No, the two parts do actually work with the Iron Grenadier cannon. I have one on my desk right now in the proper configuration. However, it was packed separately and the fit may not be perfectly tuned in, as the IG cannon was not intendend to use the linkage from Urban Destro. It was meant to be a freely carried cannon with an underslung ammo box. The hole on the side is a standard 3mm hole used in our figures (such as Duke Urban Assault and Shadow Tracker) and can be used to customize this weapon.
Well, I just grabbed my IG figure, grabbed the smaller ammo box and promptly slid it into the gap between the tab on the underside of the barrel, and the block on the underside of the receiver. AND BY GOLLY IT FITS!
I knew there was sumthin' I was missing!