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The break-action is often constrained to One drawback of the break-action design is its
rimmed cartridge chamberings because of de- inability to handle high pressure cartridges. The
sign constraints. Break-action firearms use a breech locking mechanism often consists of a
“flat” extractor to push against the rim of the single locking lug that is only capable of safely
cartridge in order to extract and eject it (other containing the pressure from shotgun and low
firearms use a hooked extractor to pull the case pressure pistol and rifle rounds. Some newer de-
from the chamber). This allows the break-style signs have introduced additional locking lugs or
action the ability to extract multiple cartridge a crossbolt to help distribute some of the load
cases of different calibers at the same time. generated from higher power cartridges.
The break-style action is one of the oldest
breechloading designs that is still in use today
and is popular with hunters and the sporting
community. The break-action design requires
a very compact receiver, which allows the use
of longer barrels and creates an overall length
that can still be easily maneuvered. The versatil-
ity of combo guns allows the user to hunt vari-
ous types of game without the need for multiple
firearms. Over-under shotguns dominate trap
and skeet competitions and are very popular for
hunting foul. The break-action is also known as
the top-break or break-barrel action.
ROLLING-BLOCK ACTION
The rolling-block action gets its name from the
fact that the breechblock will “roll” in and out
of battery. The breechblock, which features one
side that is shaped like an arc, rotates around
a pin and exposes the chamber when opened
and completes the chamber when closed. The
rolling-block action is used with pistols, rifles,
and shotguns. The rolling-block action system
is a manual action that must be manipulated by
the operator in order to complete the cycle of
operations. With an empty and locked action,
the cycle of operations for a rolling-block fire-
arm is as follows:
• The hammer is manipulated into
the “cocked” position, freeing the
breechblock.
Figure 22: Rolling-block cycle of operations.
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