Arsenal's SLR106 is a 5.56x45mm AK. I've used them in classes and can vouch for the model as long as you use gen 2 mags.

I personally don't subscribe to the "scrounged or traded for" gun parts or ammo idea. Who, in their right mind, would turn loose of ammo? The person who they trade it to could use it to take everything they have.

Ammo and parts are something you buy and store BEFORE something happens.

The dependence on optics is a concerning trend. Optics are force multipliers and have their place, but bombproof back up iron sights (read: NO PLASTIC SIGHTS) are critical.