The M4 carbine is a family of firearms tracing its lineage back to earlier carbine versions of the M16 rifle, all based on the original AR-15 rifle designed by Eugene Stoner and made by ArmaLite. The M4 is a shorter and lighter variant of the M16A2 assault rifle, with 80% parts commonality.
In 28 Weeks Later
<gallery> File:High_and_left.jpg|The sight of Sergeant Doyle's M4 rifle. File:Doyle_with_m4.jpg|Doyle with his M4A1 Carbine. File:How_do_i_fire.jpg|A soldier guard's M4 rifle. File:M4a1_slung.jpg|An M4A1 slung over a soldier's back. File:Stay_back.jpg|Two soldiers armed with M4A1 rifles. File:Doyles_m4_on_ground.jpg|Doyle's M4 rifle beside him on a rooftop. File:Aim_and_escape.jpg|Doyle aiming his M4 in the streets of District One. File:M4_by_side.jpg|Doyle with his M4 in Regent's Park. File:Another_aiming_doyle.jpg|Doyle aiming his M4 at Infected outside Regent's Park. File:Scary_night_vision_m4.jpg|The night vision scope on Doyle's M4.