I did a dog pants and made Frank's shotgun using pimp my gun. They don't have drum mags on the new version and technically there's no sight on Frank's gun because his eyes do it all instead, but it looked better.
It's an acr receiver and stock, a hk416 front rail, a bayonet in some scope rings, a pistol grip off an m4 and a flash hider for the fat shotgun barrel.
Yeah the stock with the cheek weld that looks like it extends up is the biggest cue to me that it looks like a SCAR. Looks pretty tacticool* to me anyways.