Manual

20 | Page
SECTION 4 FUNCTION
The Daniel Defense M4 Carbine has a semi-automatic action.
With the action cocked, chamber loaded, and selector lever
set to “FIRE” the firearm may be fired by squeezing the
trigger. The trigger rotates, disengaging the trigger sear
surface from the hammer. The hammer spring drives the
hammer forward to strike the firing pin, which in turn strikes
the primer in the base of the cartridge, igniting the primer
composition which ignites the main powder charge.
High pressure gases push the bullet down the barrel where
rifling grooves impart a stabilizing spin to the bullet. As a
bullet passes the gas port (a small hole in the barrel below
the front sight) gas is tapped off, flows through the gas tube,
into the bolt carrier chamber driving the bolt carrier group
rearward. As the bolt carrier moves to the rear the firing pin
is withdrawn into the bolt while the cam track in the bolt
carrier acts upon the bolt cam pin, causing the bolt to rotate
until its locking lugs are no longer in engagement with the
lugs of the barrel extension.
The bolt is now unlocked and is carried rearward by the bolt
carrier.
The extractor extracts the spent case and holds it against the
face or bolt until the ejector throws the spent case through
the ejection port.
The bolt carrier group continues rearward, compressing the
action spring and returning the hammer to its cocked