How do you aim the m4 carbine?
The M4, like most US military rifles made in the past 70 years,
uses a ring and post sight system. The front sight, a post, is
placed on your target, being elevated or depressed to account for
range, and centered in the circle of the rear ring sight. Do a
Google search for FM m16 rifle, and find the Field Manual for the
rifle- it shows illustrations of sight alignment and sight
picture.