Page 92 - FAT 105 4.17 MOODLE

cycle the action. The recoil-operated action is with several subcategories of action. The three
not as simple as the blowback but is still less major categories of recoil-operated actions are
complex than other action styles. There are sev- long recoil, short recoil, and inertia.
eral styles of recoil-operated firearms based on
• Long Recoil – The long recoil-operated
the movement of the barrel and the bolt/slide
action gets its name from the fact that
and the way the chamber locks.
the barrel and bolt/slide travel near to
Like other action types that rely on the energy all the full distance of the action’s travel.
created by a discharging cartridge, recoil-oper- This differs from other recoil-operated
ated action firearms can be finicky with certain actions where the barrel may only move
ammunition types. Recoil-operated firearms are a short distance compared to the rest of
also susceptible to human error. Most recoil- the action. The long recoil action is very
operated firearms are designed to run with a unique in design and was very popular
th
general range of ammunition that will generate early in the 20 century.
enough energy to sufficiently cycle the action;
The long recoil action utilizes a spring
but rounds that are designed to be stronger or
barrel and one-piece bolt design. During
weaker than normal can cause malfunctions in
discharge, the pressure inside the cham-
a recoil-operated firearm. Also, because the fire-
ber will cause the locking surfaces to
arm is designed for part or most of the action to
hold it closed until the bullet has exited
move in order to cycle the action, the operator
the bore and pressure has dropped. The
can cause malfunctions by not securing it during
barrel will begin to move backward, driv-
discharge. If the entire firearm is allowed to re-
ing the bolt with it. The barrel and bolt
coil too much instead of just the parts that need
will continue to move backward until
to move, the energy needed to cycle the action
they bottom out against the rear of the
will be dissipated by the entire firearm moving.
receiver, at which point a return spring
Recoil-operated firearms are some of the most
will drive the barrel forward while the
common action types used with modern day
bolt and empty case are held in place by
semi-automatic firearms. Recoil operation can
a catch.
be divided into three major operation types,

Figure 14a: Long recoil-operated action.

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