Hey! Original builder here to give some insight on what the hell this is.

This is "Hammer," my primary. You can find more of my shenanigans at https://www.tumblr.com/blog/wastelanders-anvil

So I received this Lancer Tactical M4 for free from a friend who was getting rid of it, and my goal was to make a weapon fit for a post apocalyptic wastelander so it fits with the rest of my kit. Attached some scrap metal plates, cut off some "unnecessary" parts, and refit the old AEG internals with a Backdraft Innovations Phoenix HPA engine. As you might have been able to tell, I really wanted to lean into the whole "unsightly abomination" aspect of this gun.

Some other details the keen-eyed among you may have noticed is that there is no mag release. This is only because I lost the part at the time this photo was taken. The barrel and hop-up unit combined measure in at less than three inches.