Page 131 - FAT 105 4.17 MOODLE

implies, a single-stage trigger only has one stage Another example would be a 1911-style trigger
before the break. There is no take-up or pre- system. The 1911 uses a two-stage, single-ac-
travel, but only the wall. When the trigger is tion trigger. The design relies on the first stage
pressed, all that is felt is creep before the break. to prevent accidental discharge because the ac-
A two-stage trigger is so named because of the tual weight of the break is fairly light. When
fact that the trigger has a pre-travel stage before the trigger is pressed you will feel a very short
the break. When the trigger is pressed, there is take-up, with around 1 – 2 lbs of resistance be-
an initial pre-travel before reaching the wall. fore reaching the wall. An additional 1 – 2 lbs of
When the trigger reaches the wall, slightly more pressure is required to reach the break. Although
pressure is required to achieve the break. the overall weight of the pull is fairly light, the
addition of the first stage adds a degree of safe-
Both systems have their own advantages and
ty to the system. This allows for a light trigger
disadvantages and are used in different applica-
with a short travel that is safe.
tions. Various designs use both actions and stag-
es to achieve the perfect pull for their desired With double-action systems with the hammer/
results. For example, the AR-15-style firearms striker down there typically is no pre-travel.
utilize single-stage, single-action trigger sys- Any travel in the system is transferred to cock-
tems. The design relies on the weight of the pull ing the hammer/striker. If the hammer/striker
and the large amount of creep to safely function. is already cocked, there may be some take-up, as
When the trigger is pressed, you will feel about the trigger must move until contacting the ham-
1
4 – 7 lbs of resistance and between a ⁄16” and ⅛” mer/striker. The double action makes the extra
of creep before the break. Although the weight stage redundant; therefore double-action sys-
is fairly heavy and there is a significant amount tems hardly ever feature a two-stage operation.
of creep, the whole pull is fairly short with a
short reset, which allows for fairly fast rapid fire.

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