Here's a little more spiced up version of the North Hollywood Shootout Dissipator that Emil Mătăsăreanu used, parts list goes as follows:

A2 Bird Cage

LMT rifle length 18in barrel cut down to 16in and gas ports opened up to .093

Colt A1 triangle handguards

Colt A2/ 727 upper with M4 feed ramps

Metrolight A2 night sights

Colt BCG and charging handle with a Wilson combat extended release

Bushmaster Lower with Franklin Arms Binary trigger

Colt 2 position buffer tube and CAR-15 stock

 

Comes with a 100 round Beta C mag, 30rd PMAG and a Center industries 30rd USGI mag

 

This thing shoots like a laser but due to circumstances I have to get rid of it. Can ship for an extra $80