I couldn't find an ak47 that was easy to print, so I took a model I found online and turned it into one shell with makeprintable.com. Then I split it in half to print horizontally with minimal supports, and I split it in several parts to fit my MK2s. The resulting pieces can be joined by any strong contact cement.
Maybe I should add holes for alignment rods.
You can check out what I'm up to at https://www.instagram.com/mecompreunaimpresora3d/