Page 140 - FAT 105 4.17 MOODLE
P. 140
• Fire Control Group (FCG) – If the ac- action), bolt/charging handles and bolts/
tion is the engine of a firearm, the fire slides and magazine catches/releases and
control group is the ignition that turns takedown levers.
the action on and the throttle that keeps
The manual safety/selector is used to acti-
it moving. When the trigger is pressed to
vate various modes of operation, depend-
the rear of the firearm, it initiates a se-
ing on the specific model. The basic types
ries of events that lead to ignition of the
of operation the safety/selector permits
cartridge. As previously discussed, there
are Safe, Fire, Burst, or Auto. When the
are two basic kinds of fire control groups
safety/selector is set in the Safe position,
(hammer and striker-fired) and several
the FCG becomes inoperable. Depending
modes of operation (single- and double-
on design, the safety/selector will block
action/single- and two-stage). The most
the trigger/hammer/sear’s movement or
common types of fire control group parts
will disconnect the trigger from the rest
are triggers, hammers/ strikers, sears, firing
of the FCG. A tab or lug on the safety/
pins, springs, and various types of linkage.
selector will engage the trigger/hammer/
• Controls – If the FCG is like a firearm’s sear directly, completely constraining its
ignition, the controls are like the brakes, movement, or will engage some type of
clutch, and gear shift knob. The controls connector or linkage that will detach the
are used to select the firing mode (Safe, trigger from the other components. When
Fire, Auto, Burst), remove and replace a the trigger is pressed, depending on de-
magazine, load and lock the breech open, sign, it will feel solid and not move or it
or open the action completely. The con- will feel light and move freely. The differ-
trols are used to complete functions other ence between the safety and the selector
than firing. The most common controls lies in the function of the firearm. Manual
are manual safeties/selectors (there may and semi-automatics typically employ a
be other automated, redundant safeties safety that has two modes: Safe and Fire.
that are activated by other parts of the Automatic and burst fire guns will use a
Figure 14: Various fire control group parts.
136
