when it counts™ ™ OWNERS MANUAL: HANDLING & SAFETY INSTRUCTIONS READ THE INSTRUCTIONS AND WARNINGS IN THIS MANUAL CAREFULLY BEFORE USING THIS FIREARM; DO NOT DISCARD THIS MANUAL. This instruction manual should always accompany this firearm and be transferred with it upon ownership, or when the firearm is loaned or presented to another person. 11SIG455_M400MiniManual.
State-By-State Warnings 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: WARNING “Children are attracted to and can operate firearms that can cause severe injuries or death.
when it counts™ MAINE: “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.
NEW JERSEY: “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.
when it counts™ TEXAS: “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.
WARNING - LOCKING DEVICES 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.
when it counts™ FIREARMS SAFETY IS YOUR RESPONSIBILITY 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.
TABLE OF CONTENTS Topic Page State by State Warnings 2-5 Locking Device 6 General Safety Information and Mechanical Characteristics 14 Basic Rules of Safe Firearms Handling 15 1.0 Safety Information 14 1.1 Protect your Eyes and Ears 16 1.2 Ammunition 16 2.0 Mechanical Characteristics and Rifle Theory 21 2.1 Rifle Description 21 2.1.1 General 21 2.1.2 Barrel with Receiver and Gas System 21 2.1.3 Bolt and Bolt Carrier Assembly 22 2.1.
when it counts™ Topic Page 2.1.7 Buttstock Operation 26 2.1.8 Trigger Guard Operation 30 2.1.9 Sights 32 2.1.10 Magazine 39 2.2 Technical Specification 40 2.2.1 Operation of Fire Control Selector /Safety 41 3.0. Handling 43 3.1 Important Instructions 43 3.2 Loading the Magazine 44 3.3 Loading the Rifle 45 3.4 Reloading the Rifle (partially loaded magazine in rifle) 46 3.5 Reloading the Rifle (empty magazine in rifle) 47 4.
Topic Page 6.0 Procedures in case of a Stoppage 6.1 Failure to Fire (Cold Rifle) 6.2 Failure to Fire (Hot Rifle) 52 52 53 7.0 Field Strip Disassembly 55 7.1 Detailed Disassembly of the Bolt Carrier and Bolt 56 7.2 Extractor Removal 57 7.3 Hand Guard Removal 58 7.4 Removal of Recoil Buffer and Action Spring 59 8.0. Cleaning 60 8.1 Bore 61 8.2 Chamber 61 8.3 Bolt 62 8.4 Bolt Carrier 62 8.
when it counts™ Topic Page 9.2 Extractor 66 9.3 Bolt to Bolt Carrier 67 9.4 Bolt Carrier to Upper Receiver 70 9.5 Rejoining Upper and lower Receivers 71 10.0 Perform a Function Check 72 11.0 Lubrication 73 12.0 Transportation and Storage 75 13.0 Service and Replacement Parts Policy 76 14.0 Shipping Firearms for Repair 78 15.0 Parts Diagram 80 16.0 Parts List 81 SIG SAUER Limited Lifetime Firearms Warranty www.sigsauer.
WARNINGS OF GREAT IMPORTANCE ARE FOUND WITHIN THIS MANUAL Locking Devices Alterations Manual Safety Ammunition Lead Exposure Handling 6 13 25 17, 20 20 43 Loading Firing Storage Parts Purchasers Shipping 45 48 75 77 79 OTHER CAUTIONS AND WARNINGS APPEAR THROUGHOUT THE MANUAL FIREARMS ARE DANGEROUS WEAPONS READ THE INSTRUCTIONS AND WARNINGS IN THIS MANUAL THOROUGHLY AND CAREFULLY BEFORE USING. 12 11SIG455_M400MiniManual.indd 12 www.sigsauer.
when it counts™ WARNING - ALTERATIONS 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. DO NOT ALTER ANY GUN www.sigsauer.com 11SIG455_M400MiniManual.
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.
when it counts™ THE BASIC RULES OF SAFE FIREARMS HANDLING 1. ALWAYS treat every gun as if it were loaded. 2. ALWAYS be sure the barrel is clear of any obstruction. 3. ALWAYS be sure of your backstop, what lies beyond, and the safety of bystanders before you shoot. 4. ALWAYS use clean, dry, original factory-made ammunition of the proper type and caliber for your gun. 5. ALWAYS wear ear protection and safety glasses when shooting. 6.
1.1 Protect Your Eyes And Ears 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. 1.2. Ammunition 1.
when it counts™ WARNING – AMMUNITION (CARTRIDGE) NOTICE SIG SAUER Inc. SPECIFICALLY DISCLAIMS RESPONSIBILITY FOR ANY DAMAGE OR INJURY WHATSOEVER OCCURRING IN CONNECTION WITH, OR AS A RESULT OF, THE USE IN ANY SIG SAUER FIREARM OF FAULTY, NON-STANDARD, “REMANUFACTURED” HAND LOADED (RELOADED) AMMUNITION, OR CARTRIDGES OTHER THAN THOSE FOR WHICH THE FIREARM WAS ORIGINALLY CHAMBERED. 3.
5. Bullets can become lodged in the barrel: • If the cartridge has been improperly loaded without propellant 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 it counts™ 8. Do not oil cartridges, and be sure to wipe the chamber clean of any oil or preservative before commencing to shoot. Oil interferes with the friction between cartridge case and chamber wall that is necessary for safe functioning, and subjects the firearm to stress similar to that imposed by excessive pressure. 9. Use lubricants sparingly on the moving parts of your firearm. Avoid excessive spraying of any aerosol gun care product, especially where it may get on ammunition.
WARNING - AMMUNITION Death, serious injury, and damage can result from the use of wrong ammunition, bore obstructions, powder overloads, or incorrect cartridge components. Always wear shooting glasses and hearing protectors.
when it counts™ 2.0. Mechanical Characteristics and Rifle Theory 2.1 Rifle Description 2.1.1 General The SIG M400 rifle is a direct impingment rifle with a rotary bolt mechanism capable of semi-automatic or full automatic fire operation. Semi-Automatic is defined as one round being fired each time the trigger is pressed to the rear until the magazine is depleted of ammunition. The rifle is chambered in 5.56x45mm NATO and is compatible with .223 Remington ammunition. 2.1.
2.1.3. Bolt/Bolt Carrier Assembly The bolt carrier guides the bolt and controls locking and unlocking by means of the cam pin. The bolt carrier incorporates a carrier key that transfers gas from the gas tube to the belt carrier assembly. The bolt carrier is responsible for cocking the hammer. Cam Pin Bolt Carrier Bolt FIG 2 BOLT CARRIER The bolt houses the firing pin, the extractor and the ejector. It incorporates locking lugs that lock the bolt into the barrel extension.
when it counts™ 2.1.4. Hand Guard The hand guard protects the barrel and the gas system from damage and provides protection from barrel heat. The FIG 4 HAND GUARD ASSEMBLY ON RIFLE www.sigsauer.com 11SIG455_M400MiniManual.
2.1.5. Lower Receiver Assembly and Butt stock The lower receiver assembly contains the fire control mechanism, bolt catch, magazine well, magazine release, pistol grip, sling attachment points, and butt stock assembly. The fire control selector is ambidextrous along with the magazine catch. The fire control selector has two positions, SAFE-SEMI. SAFE - Trigger is locked and rifle cannot be fired. SEMI - The rifle will fire one shot with each press of the trigger.
when it counts™ MANUAL SAFETY “ON” MANUAL SAFETY “OFF” FIG 6 FIRE CONTROL SELECTOR POSITION SAFE-SEMI WARNING - MANUAL SAFETY: Keep the safety “ON” unless actually firing. Always move the safety to its intended position and check it. The safety is not “ON” unless it is completely “ON.” Never depend on a safety mechanism or any other mechanical device to justify careless handling or permitting the rifle to point in an unsafe direction.
2.1.7. Butt Stock Operation The SIG M400 is equipped with a telescoping butt stock. The butt stock may vary depending on the model. The butt stock on the SIG M400 may vary depending on the specific model you have. The butt stock provides for easy adjustment of the length to accommodate the individual shooter or for storage. To adjust the length of the butt stock, fully depress the release latch and pull the stock rearward to extend or push the stock forward to collapse.
when it counts™ Release Latch FIG 13 BUTT STOCK COLLAPSED AND FULLY EXTENDED www.sigsauer.com 11SIG455_M400MiniManual.
To remove the butt stock: Depress the adjustment lever to disengage the release latch and slide the stock to full extension. Grasp the release latch and pull down as you slide the stock from the receiver extension. FIG 14 BUTT STOCK REMOVAL 28 11SIG455_M400MiniManual.indd 28 www.sigsauer.
when it counts™ To re-install the butt stock: DO NOT FORCE THE PARTS TOGETHER! Align the stock body with the receiver extension and Gently slide the butt stock onto the receiver extension until it stops (About 2 1/8”) Grasp the release latch and pull down as you slide the stock the rest of the way on to the receiver extension. Check to see that the stock moves to all positions locks into place. FIG 15 INSERT VIEW OF BUTT STOCK INSTALLATION www.sigsauer.com 11SIG455_M400MiniManual.
2.1.8. Trigger Guard Operation 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. It should be returned to its normal position immediately.
when it counts™ WARNING: DO NOT MANIPULATE THE TRIGGER GUARD UNLESS THE FIRE CONTROL SELECTOR IS ON “SAFE” AND THE RIFLE IS UNLOADED. www.sigsauer.com 11SIG455_M400MiniManual.
2.1.9. Sights The SIG M400 rifle features integrated Mil-Std M1913 rails on the upper receiver. These rails may be used for attaching a variety of sighting systems, both optical and fixed. These sights are designed to provide a simple, durable sighting solution should you decide not to use an optical device. FIG 17 SIG M400 SIGHT ASSEMBLY 32 11SIG455_M400MiniManual.indd 32 www.sigsauer.
when it counts™ Adjustable Rear Sight SHORT RANGE - This “larger aperture is used for 0-200 meters range. As shown, the sight is set for 0-200 meters. This larger aperture is only used when the rear sights all the way down. In other words, the 300-meter mark is aligned with the mark on the left side of the receiver. FIG 18 SIGHT ADJUSTMENT FOR 0-200 METERS NORMAL RANGE -The aperture is unmarked and used for most firing situations.
Zeroing your SIG M400 a The front sight post and rear sight windage knob are adjusted so you can hit your point of aim at 300 meters. b The unmarked aperture must be in the up position. c. The 300-meter mark is aligned with the mark on the left side of the receiver. This will read 6/3 for the M400. 34 11SIG455_M400MiniManual.indd 34 www.sigsauer.
when it counts™ Zeroing Adjustments 1. During zeroing procedures, only the front sight post and windage knob are adjusted to move the strike of the bullet on the target. 2. If you are zeroing on a 25-meter range, the rear sight elevation knob is adjusted in accordance to whichever weapon you are using. 3. Detailed zeroing procedures are on the target and the following pages. FRONT SIGHT - The front sight post is moved up or down when zeroing the weapon.
Changes in point of impact FOR ELEVATION (per click) FOR ELEVATION (per click) CLICKS IMPACT DISTANCE CLICKS IMPACT DISTANCE 1 0.9 cm (3/8 in.) 25 meters 1 1.2 cm (1/2 in.) 25 meters 2 3.5 cm (1 3/8 in.) 100 meters 2 4.8 cm (1 7/8 in.) 100 meters 3 7.0 cm (2 ¾ in.) 200 meters 3 9.6 cm (3 ¾ in.) 200 meters FOR WlNDAGE KNOB (per click) FOR WlNDAGE KNOB (per click) CLICKS CLICKS IMPACT DISTANCE IMPACT DISTANCE 1 0.3 cm (1/8 in.) 25 meters 1 0.5 cm (3/16 in.
when it counts™ Zeroing Adjustments (Cont) To remember your correct zero windage, note location of windage scale and windage knob pointer (heavy mark on outside of knob). Do not center rear sight aperture for inspections. Keep your correct bat&sight zero windage on your weapon at all times. By following the steps below and establishing a zero at 25 meters, your sights will be set with a 300-meter battlesight. NOTE: Do not move front sight post at this time.
4. Now rotate the elevation knob clockwise (up) two clicks for the SIG M400 rifle. The elevation knob should remain aligned on the 300 meter setting for the SIG M400 carbine. Any further corrections required in elevation are made to the front sight post only. 5. Aim at target center. Adjust front sight and rear windage to move shot group center as close as possible to the while dot in the center of target. 6.
when it counts™ 2.1.10. Magazine The SIG M400 rifle ships with (1) one thirty (30) round aluminum magazine. The SIG M400 is compatible with most M16/ AR15 type magazines. Aftermarket magazines should always be checked for proper fit and function prior to using them with the SIG M400 rifle. FIG 20, 20 AND 30 RD MAGAZINE www.sigsauer.com 11SIG455_M400MiniManual.
2.2. Technical Specifications CALIBER 5.56 x 45mm NATO OVERALL LENGTH 39.5” LENGTH WITH STOCK COLLAPSED 36.0” OVERALL HEIGHT 7.31” BARREL LENGTH WITH FLASH SUPPRESSOR 16” BARREL CONTOUR Mil-Spec M4 Profile RIFLING LEAD 1 in 7” NUMBER OF GROOVES 6 MUZZLE BRAKE Mil-Spec SIGHT RADIUS 14.2” WEIGHT WITHOUT MAGAZINE 6.5 lbs MAGAZINE TYPE AR-15 Type Aluminum MAGAZINE CAPACITY 30 TRIGGER Mil-STD TRIGGER PULL 7.6 lbs Specifications are approximate and subject to change.
when it counts™ 2.2.1 Operation of Fire Control/Safety Four basic fundamentals of safe firearm handling should be applied during any and all activities described in this manual. Treat every firearm as if it were loaded. Always keep the muzzle pointed in a safe direction until ready to shoot. Keep your finger off of the trigger and out of the trigger guard until ready to fire. Be aware of your target and what is beyond it.
SEMI – The trigger is no longer locked and the rifle WILL FIRE one shot with each press of the trigger until either the operator stops firing or the ammunition is expended from the magazine. MANUAL SAFETY “OFF” FIG 22 FIRE CONTROL SELECTOR ON SEMI The fire control selector should always be in the SAFE position except when the operator is actually going to fire the rifle, and upon completion of firing. 42 11SIG455_M400MiniManual.indd 42 www.sigsauer.
when it counts™ 3.0 Handling 3.1 Important Instructions • • • • • • • Before manipulating the weapon, ensure the fire control lever is in the “S” (SAFE) position and the trigger guard is in the closed position. Use only factory-new ammunition which corresponds to the caliber of the weapon. During all manipulations of the rifle, point the weapon in a safe direction. Do not place your finger on the trigger until the target has been verified and you intend to shoot.
3.2 Loading the Magazine FIG 23 516 MAGAZINE BEING LOADED 1. Ensure the magazine is the proper type and caliber for the rifle; 2. Place a round between the feed lips and press down- ensure the bullet is facing the front of the magazine; 3. Ensure the cartridges are fully seated to the rear of the magazine by tapping the back of the magazine in the palm of the hand. 44 11SIG455_M400MiniManual.indd 44 www.sigsauer.
when it counts™ 3.3 Loading the Rifle 1. Ensure the safety lever is in the “S” (SAFE) position; 2. Insert the magazine and check that it is properly seated; 3. Bolt forward: Pull the charging handle back fully and release; or 4. Bolt locked open: Depress bolt catch fully to release bolt. WARNING: DO NOT LOAD A RIFLE WITH A HOT CHAMBER BECAUSE A ROUND MAY “COOK” OFF (i.e., a round may detonate (fire) unexpectedly just because it is exposed to the heat of the rifle’s chamber).
3.4 Reloading the Rifle after firing has commenced (partially loaded magazine still in rifle). 1. Place fire control selector on SAFE. 2. Keep muzzle pointed in a safe direction and finger out of the trigger guard! 3. Depress magazine catch and remove magazine. FIG 25 MAG CATCH BEING DEPRESSED LEFT AND RIGHT SIDE 4. Insert loaded magazine and ensure it is seated properly. 46 11SIG455_M400MiniManual.indd 46 www.sigsauer.
when it counts™ 3.5 Reloading the Rifle after firing has commenced (bolt locked open, empty magazine still in rifle). 1. Place fire control selector on SAFE. 2. Keep muzzle pointed in a safe direction and finger out of the trigger guard! 3. Depress magazine catch and remove magazine. 4. Insert loaded magazine and ensure it is seated properly. 5. Release the bolt by either: a. Depressing bolt catch fully releasing the bolt; b. Grasping the charging handle, retracting it slightly and releasing it.
4.0 Cycle of Operation Ready to Fire Condition The SIG M400 “Ready to Fire” condition is described as a loaded magazine properly seated into the magazine well, a live cartridge loaded into the chamber, the fire control selector place on “SAFE”. WARNING - FIRING The bolt automatically opens and shuts quickly while firing. Keep face and hands away from it. Hot brass and powder gas is ejected quickly and can burn you. The rifle should be fired from the right shoulder.
when it counts™ 4.1. Firing Rotate the fire control selector from the “SAFE” position to the “SEMI” position. Pressing the trigger rearward releases the hammer causing it to strike the firing pin, impacting the cartridge primer. CAUTION: THE SIG M400 IS A SEMI-AUTOMATIC RIFLE AND WILL AUTOMATICALLY RELOAD THE NEXT CARTRIDGE IN THE MAGAZINE AFTER THE CHAMBERED CARTRIDGE IS FIRED FOLLOWING ONE PRESS OF THE TRIGGER. THE RIFLE WILL NOW BE READY TO FIRE AGAIN ONCE THE TRIGGER IS RELEASED. 4.1.1.
4.1.2. Cocking of the Hammer 1. As the bolt carrier assembly continues rearward the bottom surface of the bolt carrier cocks the hammer rearward. 2. The hammer is then captured by the disconnect and held in place. 4.1.3 Chambering and Locking 1. Once the bolt carrier reaches its full rearward travel the buffer and recoil spring force the bolt carrier assembly forward. 2. As the bolt carrier assembly moves forward the next cartridge is stripped from the magazine and loaded into the chamber. 3.
when it counts™ 5.0. Unloading ALWAYS MAKE SURE THE MUZZLE IS POINTED IN A SAFE DIRECTION! 1. Ensure the fire control selector is rotated to the “SAFE” position. 2. Remove the magazine by depressing the magazine catch; and 3. Retract the charging handle locking the bolt carrier assembly to the rear; and 4. Visually and physically inspect the chamber to verify it is empty. Remember to clear the chamber after the magazine is removed.
TO CLEAR A STOPPAGE (JAM) 6.0. Procedures In Case of a Stoppage A “Stoppage” is an interruption in the cycle of operation as depicted in Section 4.0. A stoppage can normally be repaired by the operator by performing one of the following immediate actions described. 6.1. Failure to Fire (Cold Rifle) Trigger is pressed, hammer falls, rifle does not fire. 1. Ensure the magazine is properly seated in the magazine well by applying upward pressure and then pulling down on the magazine. 2.
when it counts™ 6.2. Failure to Fire (Hot Rifle) Trigger is pressed, hammer falls, the rifle does not fire. 1. Keep the muzzle pointed down range, place the rifle on SAFE, remove the magazine, if you cannot extract the loaded cartridge within ten (10) seconds you must wait a minimum of 15 minutes before handling the rifle. 2. Upon completion of the 15 minutes, retract the charging handle all the way back and observe the ejection of the cartridge; and 3.
6.4. Feedway Stoppage (Jam) A feedway stoppage occurs when one or more rounds are trapped in the upper receiver and stop the cycle of operation. To clear this problem: 1. Place the rifle on SAFE. 2. Remove the magazine (You might have to pull downward with some force to remove the magazine from the magazine well due to the jammed cartridges). 3. Cycle the bolt carrier assembly several times to clear any rounds from the receiver; and 4.
when it counts™ 7.0. Field Strip Disassembly 1. Unload and clear the rifle per section 5.0. 2. Ensure the bolt carrier assembly is forward and the fire control selector is placed on SAFE. 3. Press the takedown pin from left to right until it stops (It is held into the lower receiver by a detent and will not pull free from the receiver). Takedown Pin Pivot Pin FIG 27 THE TAKEDOWN PIN AND PIVOT PIN 4. Press the Pivot Pin (front pin) from left to right until it stops at the detent. 5.
7.1. Detailed Disassembly of the Bolt Carrier and Bolt. 1. Remove the firing pin retaining pin from the left side of the bolt carrier. A small punch might be needed for this procedure. 2. Tilt the bolt carrier upward and catch the firing pin as it slides out of the rear of the bolt. 3. Rotate the bolt cam pin ¼ turn and lift it straight up out of the bolt carrier. 4. Pull the bolt out from the front of the bolt carrier. FIG 28 INSERT DETAILED DIAGRAM OF BOLT AND BOLT CARRIER 56 11SIG455_M400MiniManual.
when it counts™ 7.2. Extractor Removal 1. Apply slight pressure to the rear of the extractor with the thumb. 2. Using a punch, or the tip of the firing pin, push out the extractor pin. from either side. 3. Remove the extractor from the bolt. Retaining Pin Extractor FIG 29 BOLT WITH EXTRACTOR REMOVED NOTE: Only separate the extractor spring from the extractor when replacement is necessary www.sigsauer.com 11SIG455_M400MiniManual.
7.3. Hand Guard Removal CAUTION: DO NOT REMOVE THE HAND GUARD ASSEMBLY UNLESS THE UPPER AND LOWER RECEIVERS ARE SEPARATED. REMOVAL OF THE HAND GUARD WILL EXPOSE THE GAS TUBE ASSEMBLY. SHOULD THE RIFLE FALL OR STRIKE A HARD SURFACE, THE GAS TUBE COULD BE DAMAGED EFFECTING OPERATION OF THE RIFLE. SEPARATING THE RECEIVERS REDUCES THE OVERALL WEIGHT OF THE RIFLE REDUCING THE RISK OF DAMAGE SHOULD THE RIFLE FALL OR STRIKE A HARD OBJECT OR SURFACE. FIG 31 EXPLODED VIEW OF HAND GUARD 58 11SIG455_M400MiniManual.
when it counts™ 7.4. Removal of Recoil Buffer and Action Spring REMOVAL OF THE RECOIL BUFFER AND SPRING IS EASIER IF THE HAMMER IS IN THE COCKED POSITION AND THE FIRE CONTROL SELECTOR IS ROTATED TO THE SAFE POSITION. ALWAYS WEAR SAFETY GLASSES WHEN HANDLING PARTS UNDER SPRING TENSION. 1. Depress buffer retaining plunger while maintaining control the buffer as you allow it to move forward from the receiver extension tube. FIG 37 PICTURE OF THUMB OVER BUFFER ASSEMBLY 2.
8.0. Cleaning 1. Your rifle is delivered factory packaged and preserved with a light coating of protective grease and oils. Before loading make certain that all packing grease and oil has been cleaned from the bore and exposed mechanism. 2. Before you begin to disassemble your firearm for cleaning, always double-check to make sure it is unloaded! 3.
when it counts™ 8.1. Cleaning the Bore 1. Run a patch soaked in solvent through the bore. 2. Allow the solvent to soak in the barrel for at least 5 minutes. 3. Move on to section 8.3 and clean the bolt while the solvent works on loosening the residue in the bore of the barrel. 4. If the barrel is heavily fouled use a cleaning rod and a brass or nylon bore brush of the proper bore diameter and clean the bore from the chamber end to the muzzle end.
8.3. Cleaning the Bolt A cotton patch or a soft toothbrush and solvent can be used to complete the following steps: 1. Clean all fouling from around the bolt locking lugs. 2. Clean all fouling from bolt body 3. Clean extractor and the extractor slot in the bolt. 4. Use pipe cleaner to clean firing pin channel. 8.4. Cleaning the Bolt Carrier 1. Clean all fouling from bolt carrier body. 2. Clean the bolt channel in the front of the carrier with a brush or cotton swabs. 8.5.
when it counts™ 8.6. Cleaning the Magazine Magazines should be cleaned whenever the rifle is cleaned as preventive maintenance. FIG 39 MAGAZINE 1. Use a brush to clean inside the body. 2. Clean with a rag and CLP then wipe dry. 3. Clean follower and dry completely. The magazine body should be kept dry. Any oil or solvent left behind will attract dirt and debris causing undue wear and possibly feeding issues. www.sigsauer.com 11SIG455_M400MiniManual.
9.0 Reassembly 9.1. Recoil Buffer and Action Spring 1. Slide the action spring over the recoil buffer and snap it into place by using a clockwise twisting motion as you press it forward. FIG 40 SPRING TO BUFFER 64 11SIG455_M400MiniManual.indd 64 www.sigsauer.
when it counts™ 2. Insert the action spring into the receiver extension tube. FIG 41 ACTION SPRING AND BUFFER STARTED INTO RECEIVER EXTENSION 3. Push the recoil buffer back into the receiver extension until the buffer retaining plunger engages the face of the buffer and holds it into the receiver extension. FIG 42 BUFFER HELD INTO RECEIVER EXTENSION www.sigsauer.com 11SIG455_M400MiniManual.
9.2. Extractor 1. Fit extractor to bolt body by holding bolt in one hand; and 2. While applying pressure with thumb over the spring end of the extractor, slide extractor pin into hole until ends are flush with bolt body. FIG 43 EXTRACTOR TO BOLT BODY 66 11SIG455_M400MiniManual.indd 66 www.sigsauer.
when it counts™ 9.3. Bolt to Bolt Carrier WARNING: THE BOLT CAM PIN MUST BE INSTALLED OR THE RIFLE WILL SUFFER A CATASTROPHIC FAILURE WHICH COULD RESULT IN SERIOUS INJURY OR DEATH TO THE OPERATOR. DO NOT INTERCHANGE BOLT ASSEMBLIES FROM ONE RIFLE TO ANOTHER. DOING SO COULD RESULT IN SERIOUS INJURY OR DEATH TO THE OPERATOR. www.sigsauer.com 11SIG455_M400MiniManual.
1. Re-insert the bolt into the bolt carrier with the extractor oriented to the right side of the bolt carrier; and FIG 44 ALIGN BOLT INTO CARRIER BODY 2. Pull the bolt forward to the unlocked position; and align the cam pin hole inserting the cam pin into the bolt; and 3. Insert the firing pin into the tail shaft of the bolt. FIG 45 CAM PIN BACK INTO BOLT AND CARRIER 68 11SIG455_M400MiniManual.indd 68 www.sigsauer.
when it counts™ CAUTION: THE FIRING PIN MUST BE FULLY INSERTED INTO THE BOLT CARRIER PRIOR TO INSTALLATION OF THE FIRING PIN RETAINING PIN. THE RETAINING PIN MUST PASS BETWEEN THE LARGE SHOULDER OF THE FIRING PIN AND THE HEAD OF THE FIRING PIN. FIG 46 FIRING PIN INSERTED INTO BOLT/CARRIER 4. Re-install the firing pin retaining pin into the bolt carrier from left to right. 5.
9.4. Bolt Carrier Assembly to Upper Receiver 1. Position the upper receiver assembly with the open bottom facing upward; and 2. Insert the charging handle into the slotted key way of the receiver and push it forward slightly. 3. Take the bolt carrier assembly with the bolt pulled completely forward (unlocked position) and set it into the charging handle. 4. Simultaneously push the bolt carrier assembly and the charging handle forward until the bolt and the charging handle lock into place.
when it counts™ 9.5. Rejoining Upper and Lower Receivers To aid in steps 1-3, manually cock the hammer by pushing it down until it is held in place then rotate the fire control selector to SAFE. 1. Position the upper and lower receivers to align the pivot pin (front pin) holes. 2. Push the pivot pin from right to left until the head of the pivot pin is flush against the receiver. You will feel it captured by the detent pin. 3.
10.0. Perform a Function Check of the SIG M400 Semi-Automatic Rifle With the SIG M400 rifle and one UNLOADED magazine perform a function check of the rifle as outlined below in steps 1-13. THE FUNCTION CHECK SHOULD ALWAYS BE DONE AFTER CLEANING AND ASSEMBLING THE RIFLE. ALWAYS VISUALLY AND PHYSICALLY CLEAR THE FIREARM FIRST! SIG M400 (SAFE/SEMI ONLY) 1. Insert an empty magazine into the magazine well until it locks into place. 2.
when it counts™ 11.0 Lubrication Using lubricant designed for use on firearms, lightly apply to the contact areas of the following components: Upper Receiver Assembly • Forward assist. • Ejection port cover spring and latch. • Charging handle latch and spring. • Front sight detent. • Rear sight windage screw and detent. www.sigsauer.com 11SIG455_M400MiniManual.
Bolt and Carrier Assembly • Extractor spring. • Tailshaft • Cam Pin. • Bolt Rings. • Locking Lugs. • Rail Surfaces, top and bottom. • Bolt bearing surface. Lower Receiver Assembly • Fire control springs, pins, detents, pivot and takedown pins. • Trigger Sear Surface, Disconnect Surface. • Buttstock release levers. • Recoil buffer • Action spring • Receiver extension 74 11SIG455_M400MiniManual.indd 74 www.sigsauer.
when it counts™ 12.0 Transportation and Storage When transporting your firearm to and from shooting activities, keep it unloaded for your safety and for the safety of others. When storing your firearm, keep it separated from ammunition, under lock and key if possible, and out of the reach of children and other inexperienced or unauthorized persons. WARNING - STORAGE: Never place or store any firearm in such a manner that it may be dislodged.
13.0. Service and Replacement Parts Policy Parts Policy Our Service Department maintains a full complement of replacement parts. Even though most gunsmiths have the knowledge, training, and the ability to make necessary repairs to your firearm, the skill and workmanship of any particular gunsmith is totally beyond our control. Should your firearm ever require service, we strongly recommend that you return it to SIG SAUER Inc.
when it counts™ WARNING - PARTS PURCHASE: It is the purchaser’s responsibility to be absolutely certain that any parts ordered from the factory are correctly fitted and installed. Firearms are complicated mechanisms and IMPROPER FITTING OF PARTS MAY RESULT IN A DANGEROUS MALFUNCTION, DAMAGE TO THE FIREARM, AND SERIOUS INJURY TO THE SHOOTER AND OTHER PERSONS. The purchaser and installer of parts must accept full responsibility for the correct adjustment and functioning of the rifle after such installation.
Service Policy If you have questions concerning the performance or servicing of your rifle, please write or call: SIG SAUER Inc. Attention: Customer Service 18 Industrial Drive, Exeter, NH 03833 Phone: (603) 772-2302 Fax: (603) 772-9082 IF YOU DO NOT UNDERSTAND THE INSTRUCTIONS FOR OPERATING YOUR RIFLE, IT IS YOUR RESPONSIBILITY TO CALL OUR CUSTOMER SERVICE DEPARTMENT AT (603) 772-2302 BEFORE USING YOUR RIFLE. 14.0.
when it counts™ 3. Package the firearm securely to prevent damage. Enclose a letter which includes your name, street address, daytime phone number, model and serial number, and a detailed description of the problem you have experienced or the work you want performed. With the exception of extra magazines, do not include scopes, mounts, or other accessories. 4. Generally, an individual may ship firearms to the manufacturer for repair or service. Some states and localities, however, prohibit this.
ORDER PARTS In the event you want to order parts for your SIG M400 rifle, contact Customer Service at (603) 772-2302. Have available the serial number of your rifle and the part diagram number for the part(s) you wish to order. 15.0 Parts Diagram 80 11SIG455_M400MiniManual.indd 80 www.sigsauer.
when it counts™ 16.
SIG SAUER® Limited Lifetime Firearms Warranty SIG SAUER warrants that the enclosed firearm was originally manufactured free of defects in material, workmanship and mechanical function.
when it counts™ Notes: www.sigsauer.com 11SIG455_M400MiniManual.
when it counts™ www.sigsauer.com For Product Service on this model, Please Call (603) 772-2302 18 Industrial Drive, Exeter, NH 03833 USA P/N 1700688 11SIG455_M400MiniManual.
