Certain states require, by law, that their own specified warning notices, in larger-than-normal type be conspicuously
included by the manufacturer, distributor, or retail dealer with firearms sold in that state. SIG SAUER sells its products
in compliance with applicable laws and regulations. Because our products may be sold in these states, we include the
following:
CALIFORNIA:
State-By-State Warnings
WARNING
“Children are attracted to and can operate firearms that
can cause severe injuries or death. Prevent child access
by always keeping guns locked away and unloaded when
not in use. If you keep a loaded firearm where a child
obtains and improperly uses it, you may be fined or sent
to prison.”
ADVERTENCIA
“A los niños atraen las amas de fuego y las pueden hacer
funcionar. Ellos pueden causarse lesions graves y la
muerte. Evite que los niños tengan accesso a las armas de
fuego guardándolas siepre con llave y descargadas cuando
no las esté utilizando. Si usted tiene una arma de fuego
cargada en un lugar en que un niño tiene accesso a ella y
la usa indebidamente, le pueden dar una multa o enviarlo
a la carcel.”
CONNECTICUT:
“UNLAWFUL STORAGE OF A LOADED FIREARM MAY RESULT IN IMPRISONMENT OR FINE.”
FLORIDA:
“IT IS UNLAWFUL, AND PUNISHABLE BY IMPRISONMENT AND FINE, FOR ANY ADULT TO STORE OR LEAVE A FIREARM IN
ANY PLACE WITHIN THE REACH OR EASY ACCESS OF A MINOR UNDER 18 YEARS OF AGE OR TO KNOWINGLY SELL OR
OTHERWISE TRANSFER OWNERSHIP OR POSSESSION OF A FIREARM TO A MINOR OR A PERSON OF UNSOUND MIND.”
“ENDANGERING THE WELFARE OF A CHILD IS A CRIME. IF YOU LEAVE A FIREARM AND AMMUNITION WITHIN EASY ACCESS
OF A CHILD, YOU MAY BE SUBJECT TO FINE, IMPRISONMENT OR BOTH. KEEP FIREARMS AND AMMUNITION SEPARATE.
KEEP FIREARMS AND AMMUNITION LOCKED UP. USE TRIGGER LOCKS.”
MARYLAND:
“WARNING: Children can operate firearms which may cause death or serious injury. It is a crime to store or leave a loaded
firearm in any location where an individual knew or should have known that an unsupervised minor would gain access to
the firearm. Store your firearm responsibly!”
MASSACHUSETTS:
“WARNING FROM THE MASSACHUSETTS ATTORNEY GENERAL: This handgun is not equipped with a device that fully
blocks use by unauthorized users. More than 200,000 firearms like this one are stolen from their owners every year in
the United States. In addition, there are more than a thousand suicides each year by younger children and teenagers who
get access to firearms. Hundreds more die from accidental discharge. It is likely that many more children sustain serious
wounds, or inflict such wounds accidentally on others. In order to limit the chance of such misuse, it is imperative that
you keep this weapon locked in a secure place and take other steps necessary to limit the possibility of theft or accident.
Failure to take reasonable preventative steps may result in innocent lives being lost, and in some circumstances may
result in your liability for these deaths.”
“IT IS UNLAWFUL TO STORE OR KEEP A FIREARM, RIFLE, SHOTGUN OR MACHINE GUN IN ANY PLACE UNLESS THAT
WEAPON IS EQUIPPED WITH A TAMPER RESISTANT SAFETY DEVICE OR IS STORED OR KEPT IN A SECURELY LOCKED
CONTAINER.”
“IT IS A CRIMINAL OFFENSE TO LEAVE A LOADED FIREARM WITHIN EASY ACCESS OF A MINOR.”
NEW YORK CITY, NY:
“THE USE OF A LOCKING DEVICE OR SAFETY LOCK IS ONLY ONE ASPECT OF RESPONSIBLE FIREARMS STORAGE. FOR
INCREASED SAFETY, FIREARMS SHOULD BE STORED UNLOADED AND LOCKED IN A LOCATION THAT IS BOTH SEPARATE
FROM THEIR AMMUNITION AND INACCESSIBLE TO CHILDREN AND OTHER UNAUTHORIZED PERSONS.”
NORTH CAROLINA:
Any person who resides in the same premises as a minor, owns or possesses a firearm, and stores or leaves the firearm
(i) in a condition that the firearm can be discharged and (ii) in a manner that the person knew or should have known that
an unsupervised minor would be able to gain access to the firearm, is guilty of a Class 1 misdemeanor if a minor gains
access to the firearm without the lawful permission of the minor’s parents or a person having charge of the minor and the
minor:
(1) Possesses it in violation of G.S. 14-269.2(b)
(2) Exhibits it in a public place in a careless, angry, or threatening manner;
(3) Causes personal injury or death with it not in self defense; or
“IT IS UNLAWFUL TO STORE, TRANSPORT, OR ABANDON AN UNSECURED FIREARM IN A PLACE WHERE CHILDREN ARE
LIKELY TO BE AND CAN OBTAIN ACCESS TO THE FIREARM.”
WISCONSIN:
“IF YOU LEAVE A LOADED FIREARM WITHIN THE REACH OR EASY ACCESS OF A CHILD YOU MAY BE FINED OR IMPRISONED
OR BOTH IF THE CHILD IMPROPERLY DISCHARGES, POSSESSES, OR EXHIBITS THE FIREARM.”
Please check with your licensed retailer, state police, or local police for additional warnings, which may be required by
local law or regulation. Such regulations change constantly, and local authorities are in the best position to advise you on
such legal matters.
This firearm was originally sold with a key- operated locking device. While it can help provide
secure storage for your unloaded firearm, any locking device can fail. All guns are designed to
fire if they are loaded and the trigger is pulled. Therefore, never install the locking device inside
the trigger guard or in any way that makes it possible to pull the trigger! Do not leave the keys
in the lock.
The ultimate responsibility for secure storage of any firearm must depend upon its owner and
his or her individual circumstances. Firearms should be stored unloaded, in a secure location,
separate from their ammunition.
NEVER INSTALL THE LOCKING DEVICE
INSIDE THE TRIGGER GUARD
To maximize effectiveness and reduce the chances of malfunction or damage to a firearm,
ALWAYS refer to the locking device’s manufacturer directions for installation and removal of the
device.
This owner’s manual is designed to assist you in learning how to use and care for your SIG SAUER® pistol properly.
Only when you are certain that you fully understand this manual and can properly carry out its instructions, should you
practice loading and firing your firearm with live ammunition. Having a gun in your possession is a full-time job; you
cannot guess and you cannot forget. You must know how to use your firearm safely.
If you have any doubts about your ability to handle or use this firearm safely, you should seek supervised instruction.
The Sig Sauer Academy™ provides all levels of firearms safety and skill training, from beginner to expert.
For more information contact:
www.sigsaueracademy.com • (603) 679-2003
Main campus: Epping, New Hampshire
Satellite Facilities: Range 82, Midland, VA
NRA Whittington Center, Raton, NM
SAFETY MUST BE THE FIRST AND CONSTANT CONSIDERATION OF
EVERY PERSON WHO HANDLES FIREARMS AND AMMUNITION.
For more information about safety, responsible firearms ownership, and shooting sports, contact: National Rifle
Association (NRA) of America, 11250 Waples Mill Road, Fairfax, VA 22030-7400 • 1-800-672-3888 • www.nra.com
This product was designed to function properly in its original condition.
Alterations can make it unsafe. Do not alter any part or add or substitute any
parts or accessories not manufactured by SIG SAUER Inc.
GENERAL SAFETY INFORMATION AND MECHANICAL CHARACTERISTICS
1.0 Safety Information
The safety warnings in this manual are important. By understanding the dangers inherent in the use of any firearm, and
by taking the precautions described herein, you can enjoy complete safety in the use of your rifle. Failure to heed any of
these warnings may result in serious injury to you or others, as well as severe damage to the firearm or other property.
SIG SAUER Inc. shall not be responsible in any manner whatsoever for malfunctioning of the firearm, physical injury or
property damage resulting in whole or in part from:
1) criminal or negligent discharge;
2) improper or careless handling;
3) unauthorized modifications;
4) defective, improper, hand-loaded, or reloaded ammunition;
5) corrosion;
6) neglect; or
7) other influences beyond our direct and immediate control.
This limitation applies regardless of whether liability is asserted on the basis of contract, negligence, or strict liability
(including any failure to warn). Under no circumstance shall SIG SAUER Inc. be liable for incidental or consequential
damages, such as loss of use of property, commercial loss, and loss of earnings or profits.
Always wear safety glasses and ear plugs or “earmuff” type protectors whenever you are shooting. Always make certain
that persons close to you are similarly protected. Unprotected eyes may be injured by powder, gas, carbon residue,
lubricant, metallic particles, or similar debris which may emanate occasionally from any firearm in normal use. Without
ear protection, repeated exposure to shooting noise may lead to cumulative, permanent hearing loss.
2.0. Mechanical Characteristics and Weapon Theory
2.1 Weapon Description
2.1.1 General
The SIG551-A1 Rifle is a gas operated weapon with a rotary bolt mechanism capable of semi-automatic, three round
burst or automatic operation. Semi-automatic means one round will fire each time the trigger is pulled until the
magazine is emptied of ammunition. Three round burst means 3 rounds will fire whenever the trigger is depressed and
held. Automatic means the rifle will continue to fire as long as the trigger is depressed or the magazine is emptied of
ammunition. Releasing the trigger in three round burst or automatic fire mode will interrupt the firing cycle. The
rifle is chambered in 5.56mm NATO and is compatible with .223 Remington ammunition.
The barrel is mechanically mated to the receiver. The flash suppressor is screwed onto the muzzle end of the barrel
which features a 0.5 x 28 TPI thread pattern. The gas block, which is fixed on the barrel, contains the gas port, locates
the gas system (gas tube and operating rod), accepts the front sight and also serves as support for the hand guards. The
receiver guides the bolt and bolt carrier, and houses the locking system. An accessory mounting rail is fixed to the upper
part of the receiver, providing an attachment point for sighting systems and other accessories.
a. Bolt Carrier: The bolt carrier guides the bolt head, controls the locking and unlocking by means of the cam, holds the
operating rod, and cocks the hammer.
b. Bolt Head: The bolt head locks the bolt assembly, houses the firing pin and extractor and feeds the cartridges from
the magazine to the chamber.
The hand guards protect the barrel and the gas system from damage and provide protection from burning. The
integrated accessory mounting rails provide attachment points for various devices, such as lights, lasers, sights, and
bipods.
The trigger casing assembly contains the internal components of the firing and safety mechanisms, bolt catch, magazine
well, magazine release, and butt stock assembly.
The safety lever, located on both sides of the trigger casing, can be set to four positions (Auto or 2 position Semi-only):
Position “S”: The weapon is locked in the safe position.
Position “F”: The weapon will fire semi auto.
Position “3”: The weapon fires 3-round burst. After each burst, the trigger must be released and then pulled again.
Position “A”: The weapon fires in the full auto mode.
The trigger guard may be released from its normal position to make the trigger accessible for shooting with gloves.
For safety reasons the trigger guard must not be released until just before firing the weapon, and after firing should be
immediately returned to the normal (closed) position.
CAUTION: Be careful of accidental discharges when inserting gloved fingers into the trigger guard.
The SIG551-A1 rifle is equipped with a side folding stock, featuring integral sling attachment point and a rubber recoil
pad.
1. The trigger guard opens to accommodate firing the rifle with gloves or mittens.
2. To open the trigger guard, depress the spring loaded pin on the front right and rotate downward.
3. When glove access is no longer required, rotate the trigger guard back into place, depressing the spring loaded pin
and ensure the trigger guard is locked closed.
DePreSS
Button
SWing
DoWnWarD
WARNING: Do not manipulate the trigger guard unless the rifle’s safety lever
is on “S” (SAFE) and unloaded.
When cycling or ejection problems are encountered due to heavy fouling, the gas valve can be moved to Position 2 by
rotating clockwise as far as the stop. In this position, a larger gas volume is released against the operating rod. The need
to use the gas valve in Position 2 is an indication that the rifle requires cleaning.
CAUTION: In the case of a hot or heavily fouled weapon, use a cartridge or auxiliary aid to prevent burns to your
fingers.
CAUTION: Firing with the gas valve in Position 2 is an exception. As soon as normal function returns, the gas
valve must be returned to Position 1. Continued operation with the gas valve in Position 2 will increase recoil and place
unnecessary stress on the rifle. The rifle should be cleaned as soon as conditions permit.
WARNING: Always ensure the rifle is unloaded and clear of ammunition
when manipulating the gas valve.
The SIG551-A1 rifle features integrated accessory mounting rails on the upper receiver
and hand guards. These rails may be used for attaching a variety of sighting systems, both
optical and fixed. The accessory rails are compatible with all Picatinny standard mounting
systems. Some models feature “emergency” flip up blade sights as a standard option.
These sights are designed to provide a backup aiming solution in the event your optics
should fail but are certainly capable of be used as the sole sighting system for the rifle.
Windage (left / right) adjustment:
Windage adjustments are made by rotating the front sight screw left or right. The adjustment screw head is located on
the left side of the front sight assembly. Adjustments are made using a 4mm allen key, available at any hardware store.
- Rotate front sight screw right (clockwise) to move impact right.
- Rotate front sight screw left (counter-clockwise) to move impact left.
One full rotation of the front sight screw will move the impact of the rounds
approximately 1” at 100 yards.
Do not adjust or otherwise manipulate any sight system on the rifle without first
confirming the magazine is removed, the rifle is on “SAFE” and fully unloaded.
Failure to heed this warning could result in unintentional discharge, resulting in injury
or death.
The rifle’s emergency sight are normally stored in a “stowed” condition to protect them from damage and prevent
interference with optical sighting systems.
To deploy the emergency sight for use, do the following:
1. Flip the rear sight blade into the “up” position. The rear sight blade is held in position
by spring tension.
3. When the emergency sight is no longer required, rotate the rear sight blades to the
stowed position.
The rifle ships with our Swiss transparent magazine. If more than one magazine is purchased, they can be attached
together by integral clips built into the magazine body.
OPERATION OF SAFETY
The SIG551-A1 has a manual safety which is located on the left and right side of the trigger casing, just forward of the
pistol grip and above the trigger. The safety levers may be operated from either side.
The safety is “ON” when the safety lever is in the “S” (SAFE)
position and the trigger guard is closed. In this position, the rifle cannot be
fired with a normal pull of the trigger.
The safety lever should always be in the “S” (SAFE) position except when
the shooter is actually firing the rifle. The safety lever should be moved
to the “S” (SAFE) position whenever the shooter ceases firing, even
temporarily.
The safety is “OFF” when the safety lever is in the “F” (FIRE)
position. When the safety lever is in the “F” (FIRE) position the rifle will fire
in the semi-automatic mode each time the trigger is pulled until all the
ammunition is expended.