YOU MUST READ THE INSTRUCTIONS AND WARNINGS IN THIS MANUAL CAREFULLY BEFORE ATTEMPTING TO OPERATE OR USE THIS FIREARM. THE FN M249S™ RIFLE OPERATES DIFFERENTLY THAN ANY OTHER RIFLE. DO NOT DISCARD THIS MANUAL. OPERATOR’S MANUAL FOR FN M249S™ SEMI-AUTOMATIC BELT-FED RIFLE Patent Pending This operator’s manual must always accompany this firearm and must be transferred with it upon change of ownership or when this firearm is loaned or presented to another person.
Important operating instructions for: FN M249S™ SEMI-AUTOMATIC BELT-FED RIFLE This operator’s manual is designed to assist you in learning how to use and maintain for your FN M249S™ rifle 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. You must know how to use your firearm safely.
CONTENTS 1. General Parts Nomenclature.......................... 4 1.1 Left Side View 1.2 Right Side View 2. Forward........................................................... 6 3. Contents of Storage Box................................ 6 4. Firearm Safety and Warnings....................... 7 5. General Firearms Safety Information........ 14 6. Description and Operation.......................... 14 6.1 Description 6.2 Operation 7. Nomenclature............................................... 15 14.
1. GENERAL PARTS NOMENCLATURE Figure 1. Left Side View Figure 2.
2. FORWARD 3. CONTENTS OF STORAGE BOX We are pleased that you have chosen an FN M249S™ autoloading rifle. The FN M249S™ represents FN’s commitment to build innovative and high quality rifles that exceed industry standards for testing, function, reliability and accuracy. 1. FN M249S™ Rifle with bipod, barrel and heat shield Based on a proven design and bearing FN’s stamp of quality, the FN M249S™ is one of the most unique firearms you will ever own.
FIREARM SAFETY INFORMATION sear block mechanism, hammer block mechanism or firing pin block mechanism. Mechanical safeties are designed to place your firearm in a safer status, and no guarantee can be made that the firearm will not fire even if the safety is in the on safe position. Mechanical safeties merely aid safe gun handling and are no excuse for pointing your firearm’s muzzle in an unsafe direction. See Section 10 for instructions on the operation of this firearm’s safety.
For law enforcement and military personnel, refer to the procedures of your department on storing your firearm. 9 If the primer is indented, the defective cartridge should be disposed of in a way that cannot cause harm. If the primer is not indented, your firearm should be examined by a qualified gunsmith and the cause of the malfunction corrected before further use. Glance down the barrel to make sure that there are no obstructions in the barrel.
CHILDREN AND NON-SHOOTERS. Closely supervise newcomers to the shooting sports. Encourage enrollment in hunting and shooting safety courses. 22 NEVER DRINK ALCOHOLIC BEVERAGES OR TAKE ANY TYPE OF DRUGS BEFORE OR DURING SHOOTING. Your vision, motor skills and judgment could be dangerously impaired, making your gun handling unsafe to you and to others. 23 READ AND HEED ALL WARNINGS IN THIS OPERATOR’S MANUAL, ON AMMUNITION BOXES AND WITH ALL ACCESSORIES THAT YOU INSTALL ON YOUR FIREARM.
15. Alternate usage of barrel assemblies to minimize wear (if available). 16. To avoid damage to equipment, DO NOT use dry cleaning solvent on plastic components. 17. DO NOT use abrasives to clean the bore, piston, gas cylinder, or gas block. 5. GENERAL FIREARMS SAFETY INFORMATION 1. Treat every firearm as if it is loaded, even if you have verified it is unloaded. 2. Keep the firearm pointed in a safe direction at all times. 3. Keep your finger off the trigger until you are ready to fire. 18.
at the factory with a rust preventative compound. This compound is not an ideal lubricant. Before using the rifle, clean the anti-rust compound from the inside of the barrel and chamber area, receiver, bolt and piston assembly, and the feed tray and feed tray cover with military-grade cleaner/lubricant as explained in Section 25. If your rifle is to be stored, it is acceptable to leave the rust preventative compound on the rifle and keep it in its original packaging.
as explained in Section 11. Note-Bracing the buttstock against your shoulder or hip will aid in holding the charging handle to the rear. FIGURE 7.A FIGURE 7.B DEVICE DOES NOT GUARANTEE THAT THERE IS NO CARTRIDGE IN THE CHAMBER. DO NOT RELY ON THE PRESENCE OF THE MANUAL BOLT LOCK DEVICE TO VISUALLY INDICATE A COMPLETELY UNLOADED AND SAFE RIFLE. THE MANUAL BOLT LOCK DEVICE IS NOT THE SAME AS A FLAG SAFETY WHICH IS INSERTED INTO A RIFLE’S CHAMBER. To remove the manual bolt lock device: 1. 5. 6. 7.
the box. This may not be allowed in all jurisdictions. Be sure of local firearm laws and regulations before using. Additionally, 200 M27 steel disintegrating links are provided to link 5.56x45mm NATO ammunition for use with the ammunition box. See Section 15.1 for linking ammunition and feeding from the box. Make sure you have verified the capacity of your ammunition belt and box before loading it in your rifle. before using.
protected by the plastic ammunition pack. Malfunctions may results. Remove the plastic ammuntion pack from rifle before filling as explained in Section 17.1. FIGURE 17 FIGURE 19 15.2 Filling the Magazine e. Once the entire belt is layered and stacked, place the layered belt into the open ammunition pack ensuring the belt stays oriented as it was stacked. Placing the ammunition box on a 45 degree angle will aid in sliding the stacked belt into the box. See Figure 21. FIGURE 21 d.
the muzzle is pointed in a safe direction. 2. If not already done, remove the magazine from the magazine well as explained in Section 15.2. FIGURE 25 FIGURE 26 pack. Place the linked belt on feed tray assembly with first round fully against cartridge stop. Ensure the closed sides of the links are facing up and the open sides of the links are facing down against the feed tray.
WARNING! THE RIFLE IS NOW READY TO FIRE BY MOVING THE SAFETY SELECTOR TO THE FIRE POSITION AND PULLING THE TRIGGER. 16. FIRING 16.1 Firing Procedures 1. 2. 3. Make sure the slide hammer is cocked and the safety selector is in the SAFE position as explained in Sections 10 and 11, and the muzzle is pointed in a safe direction. Load a cartridge into the chamber as explained previously in Section 15.
explained in Section 10 and keep the muzzle pointed in a safe direction. DO NOT open the feed tray cover. 2. Ensure the muzzle stays pointed in a safe direction and the feed tray cover remains closed in the event of a “cook off”. 3. Eject the magazine from the rifle as explained in Section 17 if it is the source of the ammunition. 4. Allow the barrel to cool for 15 minutes. 5.
feed tray cover. See Figure 33. Leave the feed tray cover open in the 45o or 90o position. 4. 5. Pull the charging handle to the rear to cock the slide hammer. The safety selector should now be placed in the SAFE position as explained in Section 10, if not already done so. FIGURE 33 8. 18.1 Sight Assembly Close the feed tray cover. 1. Rear Sight Assembly The rear sight assembly is attached to the top of the feed tray cover.
To center the rear sight aperture for elevation, turn the rear sight aperture clockwise on the rear sight leaf until it stops. Turn the rear sight aperture counterclockwise, counting the number of clicks (there will be two clicks per complete rotation), rotate the rear sight aperture until it stops in its highest position. See Figure 38. FIGURE 37 FIGURE 39 elevation knob is graduated from 3 to 10 in 100 meter increments.
IN THE SAFE AS EXPLAINED IN SECTION 10 AND ENSURE THAT THE RIFLE IS COMPLETELY CLEARED AS EXPLAINED IN SECTION 17. KEEP THE MUZZLE POINTED IN A SAFE DIRECTION. FAILURE TO FOLLOW THESE WARNINGS COULD RESULT IN SERIOUS INJURY OR DEATH. The FN M249S™ feed tray cover is equipped with an integral MILSTD 1913 rail for optics mounting on top. Use care when mounting optics to the feed tray cover. Be mindful of the location of the optic when the feed tray cover is opened.
3. 4. Simply rotate the dust cover down and closed over the ejection port until it locks closed. See Figure 45. FIGURE 45 To open the dust cover, remove the manual bolt locking device and close the bolt as explained in Section 12. Movement of the bolt and bolt carrier will open the dust cover automatically. To deploy the bipod: 1. 2.
pointed in a safe direction. 2. 3. 4. 5. FIGURE 49 With the rifle pointed in a safe direction, pull the bottom of the shoulder rest back and up. See Figure 49. When in the firing position, place the buttplate against the shooting shoulder and allow the shoulder rest to sit on top of the shoulder. The shooting position will be more stable and it will be easier to stay in a shooting position for longer. 1. 2.
1. FN M249S™ Subassemblies Identification 2. 1. Barrel Assembly 2. Buttstock Assembly 3. Guide Rod 4. Bolt Carrier / Piston Assembly 5. Bolt 6. Slide Hammer 7. Drive Spring 10. Bipod Assembly 11. Receiver Assembly 12. Forearm 13. Heatshield 14. Slide Hammer Spring FIGURE 52 3. Open the feed tray cover by squeezing in on the cover latches on the rear of the feed tray cover. See Figure 52. Leave the feed tray cover open in the 90o position. 4.
spring assembly. Then withdraw the guide rod and the two springs on the guide rod assembly from the receiver. See Figure 55. Once removed, separate the guide rod and the two drive springs. See Figure 56. FIGURE 55 7.1 Disassemble Moving Parts Assembly 1. Remove the Moving Parts Assembly To separate the bolt from the bolt carrier, press in on the bolt and rotate it so the cam lug disengages from its cam path and can be withdrawn from the bolt carrier. See Figure 59. FIGURE 59 8.
11. Remove Heat Shield 13. Remove Bipod Assembly Remove the barrel as described above. Rotate the heat shield up and off the barrel assembly. See Figure 65. DO NOT DISASSEMBLE THE BARREL ASSEMBLY BEYOND THIS. FIGURE 65 Open the bipod as described in Section 21. It can now be simply removed from the front of the receiver. Do not attempt to disassemble the bipod beyond this. See Figure 67. To remove the forearm/handguard assembly, first disassemble the rifle as described above.
.1 Receiver and Feed Tray Cover Assembly With the receiver and feed tray cover disassembled, use an all purpose brush or compressed air to remove loose debris from the feed tray cover mechanism. Use a plastic bristled cleaning brush and military-grade cleaner/lubricant to clean debris and excess lubricant from the feed tray and cover, paying close attention to not dislodge captive springs in the cover mechanism.
grade cleaner/lubricant or bore solvent to clean the chamber. Use clean bore patches with the cleaning rod and an eyelet to swab the interior of the bore and chamber clean. Leave the interior of the chamber and bore dry by swabbing it with a dry, clean patch. NOTICE! DO NOT USE A STAINLESS STEEL BORE BRUSH TO CLEAN THE BORE OR CHAMBER. IT WILL DAMAGE THE CHROME PLATING. Use the optional scraper tool to clean the gas block and gas plug. See Figures 76 and 77.
With the handguard, heat shield and buttstock assemblies removed from the receiver, use an all purpose brush and military-grade cleaner/lubricant to remove debris and excess lubricant from their exteriors. or corrode the metal components. Spray the magazine with this solvent, both inside and out to loosen debris. Warm soapy water and an all purpose brush can be used to clean the polymer components if they become excessively dirty. All to air dry or wipe dry with a clean cloth.
Hook the front end of the forearm behind the round bosses on the receiver and rotate the forearm up and onto the receiver. See Figure 85. FIGURE 88 FIGURE 89 Install Heat Shield on the middle of the receiver, just forward of the barrel latch lever. At the same time, align the gas plug to the open end of the gas cylinder. See Figure 92. FIGURE 91 FIGURE 85 Once against the receiver, slide the forearm to the rear. Press back on the barrel latch lever and install the barrel into receiver.
Install Bolt Carrier/Slide Assembly Assemble the bolt and bolt carrier as described above. Insert the piston /bolt carrier and bolt assembly into the rear of the receiver. Guide the piston into the gas cylinder in the interior of the receiver. Guide the slide hammer into the rear of the receiver aligning the guides onto the LOWER internal rails. See Figure 96.A. To aviod installing the slide hammer incorrectly refer to Figure 96.B for correct orientation. 6.
locks the trigger assembly and buttstock onto the receiver. See Figure 100. FIGURE 100 Close Feed Tray Cover 7. Assemble the rifle as described above. Ensure the safety selector is in the SAFE position. Firmly close the feed tray cover. Ensure it is locked closed. 28. OPTIONAL TOOLS AND GAUGES Rotate the buttstock up into position and press the upper take-down pin left to right until it locks the buttstock into position. See Figure 101. 27.
NOTE! WHEN NOT IN USE, THE HEADSPACE GAUGE SHOULD BE STORED IN A PROTECTIVE CASE THAT PROTECTS IT FROM CORROSION AND DAMAGE. A DAMAGED GAUGE WILL GIVE FALSE READINGS. 28.2 Breech Bore Gauge Use The optional Breech Bore Gauge included with some FN M249S™ models allows for the operator to regularly check throat erosion on the barrels. If you are unsure of throat erosion check operations, seek assistance from an FN technician or qualified gunsmith.
pistol grip to engage the 10mm nut. Turn the wrench counterclockwise to loosen and clockwise to tighten See Figure 108. 29. SERVICE POLICY AND TECHNICAL QUESTIONS If your FN product should require service, repair or for technical questions about your firearm contact: FN America Customer Support Phone 1-855-536-4872 FIGURE 108 OR VISIT US ONLINE AT WWW.FNAMERICA.COM Law enforcement and military users should contact their department or unit armorer.
30. CONTACT US 31. TECHNICAL SPECIFICATIONS If you have any questions about this operator’s manual or other FN products, contact: FN America, LLC Phone 1-855-536-4872 info@fnamerica.com • Caliber: 5.56x45mm NATO OR VISIT US ONLINE AT WWW.FNAMERICA.COM • Weight: IF YOU DO NOT UNDERSTAND THE INSTRUCTIONS FOR OPERATING YOUR FN FIREARM, IT IS YOUR RESPONSIBILITY TO CONTACT THE FN AMERICA CUSTOMER SUPPORT AT 1-855-536-4872 BEFORE USING THE FIREARM.
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