Aero Precision AR57 5.7x28mm complete upper

New Aero Precision AR57 5.7x28mm complete upper for AR-15 type rifles. This revolutionary design allows the use of 5.7x28mm ammunition on the AR15/M16 Platform. Simply attaches to AR15/M16 type Rifle/Pistol lower halves like any standard upper. Ejects through magazine well. Accepts PS90 magazines (up to 50rds for all you Prebans!). Includes buffer. Complete assembly with 16" Barrel, Flash Suppressor, Bolt and "Carbine" Buffer. Magazine not included.