Manual

SIG 556 Operators Manual 21 P/N 1511203 VER 12.7.2
3. Firearms may be severely damaged and serious injury to the
shooter or to others may result from any condition causing
excessive pressure inside the chamber or barrel during firing.
Excessive pressure can be caused by obstructions in the barrel,
propellant powder overloads, the use of incorrect cartridges or
defectively assembled cartridges. In addition, the use of a dirty,
corroded, or damaged cartridge can lead to a burst cartridge case
and consequent damage to the firearm and personal injury from
the sudden escape of high-pressure propellant gas within the
firearm’s mechanism.
4. Immediately stop shooting and check the barrel for a possible
obstruction whenever:
• You have difficulty in, or feel unusual resistance in,
chambering a cartridge;
• A cartridge misfires (does not go off);
• The mechanism fails to extract a fired cartridge case;
• Unburned grains of propellant powder are discovered
spilled in the mechanism;
• A shot sounds weak or abnormal. In such cases it is possi
ble that a bullet is lodged part way down the barrel. Firing
a subsequent bullet into the obstructed barrel can wreck
the firearm and cause serious injury to the shooter or to
bystanders.
5. Bullets can become lodged in the barrel:
• If the cartridge has been improperly loaded without pro
pellant powder, or if the powder fails to ignite (ignition of
the cartridge primer alone will push the bullet out of the
cartridge case, but usually does not generate sufficient
energy to expel the bullet completely from the barrel);
• If the bullet is not properly seated in the cartridge
case. When such a cartridge is extracted from the chamber
without being fired, the bullet may be left behind
in the bore at the point where the rifling begins.
Subsequent chambering of another cartridge may push the
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