M4 Series AR15 Carbines.
All AR15 carbines are not "M4's". To be an M4 there are some qualifying features that the carbine must have. At the same time, all M4's are not the same.
All the Carbines in this category will be manufactured with a 416 SS M4 contour barrel that includes the lightweight contour under the handguard, and the 'step' forward of the front sight base/gas block assembly for the mounting of the military M203 etc., grenade launcher system, or civilian 37mm flair launcher systems. Olympic does offer a variety of configurations in the M4 series. Take a look and chose the one that suits your needs best.