Page 106 - FAT 105 4.17 MOODLE

forced from the case, into the chamber’s
Gas-Operated throat and into the bore. As the bullet

travels through the bore, it will pass the
gas port. Some of the high pressure gas
acting upon the bullet will be diverted
The gas-operated action is unlike the blowback
by a port in the barrel. Depending on
or recoil-operated semi-automatic actions in
the model, the gas will act upon a piston,
the respect that the energy that drives the ac-
which acts upon a bolt carrier or directly
tion does not come from the cartridge itself or
against a bolt carrier. The gas will drive
the energy from discharge. The gas-operated
the piston/carrier rearward. The piston/
action relies on the expanding gas from the car-
carrier’s rearward movement will unlock
tridge being discharged to act upon the action’s
the bolt. Depending on the model, the
parts. A small amount of gas is tapped from the
bolt may unlock in various manners. (5)
bore just ahead of the chamber or farther down
the barrel. The gas operation style action is
• As the carrier moves rearward, it will
used with pistols, rifles, and shotguns. With an
move the bolt with it. As the bolt/
empty and locked action, the cycle of operations
carrier move back, the bolt will strip
for a semi-automatic gas operation style action
the empty case from the chamber and
firearm is as follows:
eject it. The carrier will also cock the
• Depending on specific model, the hammer/striker. (6)
firearm is loaded, either directly into
• Again, the action spring will drive the
an internal fixed magazine or through
bolt/slide forward, stripping a round
a removable magazine. (1)
from the magazine and driving it into
• The operator must manipulate the ac- the chamber. The chamber will once
tion by means of charging handle or again lock. (7)
slide. The charging handle/slide is pulled
• If the trigger is still being pressed, it
to the rear of the firearm, opening the
must be released to the reset position in
chamber and unlocking the breech and
order to fire the next round. If the trigger
cocking the hammer/striker. At the same
was already reset, it can be pressed again
time, a fresh cartridge has been automat-
to fire the next round. (8)
ically fed, in line with the bolt/slide. (2)
The gas-operated action has grown into the
• The action spring will drive the bolt/
preferred semi-automatic action for military,
slide forward, stripping a round from the
police, hunters, competitors, and civilians. The
magazine and driving it into the cham-
gas-operated action style is praised for its reli-
ber. Depending on the specific recoil
ability, durability, rate of fire, and in many cases,
action being employed, the chamber may
accuracy and precision. The gas-operated action
lock in various ways. Lugs on the bolt/
is also praised for its versatility.
slide and receiver are common means of
locking the chamber. (3) Unlike the blowback and recoil-operated ac-
tions, which are susceptible to malfunctions
• The trigger is pressed, releasing the
caused by under- or overpowered ammunition,
hammer/striker and discharging the
the gas-operated action tends not to be as fin-
round. (4)
icky. A majority of the gas-operated actions are
tuned to work with a variety of ammunition
• As the pressure builds inside the car-
types through port size and location, variable
tridge, the case will begin to swell and
gas blocks, and “bleed off” valves or ports. This
seal the chamber. The bullet will be

102