MR762A1 OPERATOR’S MANUAL Covering MR762A1 7.
SAFETY PRECAUTIONS CAUTION: Read these safety rules before handling the firearm! Read this operators manual before handling your firearm. The following safety rules are placed in this manual by HK as an important reminder that firearms safety is your responsibility. If handled improperly firearms can be dangerous and can potentially cause damage to property, serious injury, or death. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.
TABLE OF CONTENTS Safety Precautions...................................................... Inside Cover Clearing.........................................................................................5 Section 1 Introduction...................................................................................6 Section 2 Nomenclature and Description ....................................................7 Section 3 Function and Operation .............................................................
SECTION 1 — INTRODUCTION SECTION 2 — nomenclature & Description The thirty caliber (7.62 x 51 mm) counterpart of the 5.56 mm MR556A1, the MR762A1 also traces its lineage to the select fire HK416/HK417 model line. The MR762A1 is a semi-automatic rifle developed by Heckler & Koch as a premium level commercial/civilian firearm with match rifle capability. Like the entire line of HK416/HK417/MR556A1 long guns, the MR762A1 is a major product improvement over conventional AR-type carbines and rifles.
7. Trigger – When activated by the operator, initiates the firing sequence. Located inside the lower receiver, the trigger when squeezed with the firearm loaded and off “safe” will fire the gun, “SEMI-AUTOMATIC” will fire one round each time the trigger is pulled. The MR762A1 uses a proprietary HK two-stage trigger for optimal accuracy. 8. Trigger Guard – The trigger guard protects the trigger.
Chamber – The chamber is the area where the cartridge is seated and the initial phase of firing occurs. Assembly groups Bolt and Carrier Assembly – Provides stripping, chambering, locking, firing, extraction, and ejection of the cartridges using the recoil spring and projectile propellant gases for power. These parts are made of the highest quality steel. Bolt – The bolt locking lugs rotate and lock the barrel and bolt together prior to cartridge ignition.
Section 3 — Function and Operation The function and operation of the MR762A1 is similar to that found in semi-automatic firearms and consists of eights steps: (1) Feeding, (2) Chambering, (3) Locking, (4) Firing, (5) Unlocking, (6) Extracting, (7) Ejecting, and (8) Cocking. These eight steps are explained below with a brief description of what occurs inside the rifle during each step.
Section 4 — Sights, sight adjustment, and aiming HK DIOPTER Sights MR762A1 rifles can accommodate a wide variety of optical and mechanical (iron) sights. For models with HK Diopter rotary sight sets, the sights are installed on the MIL-STD1913 (Picatinny) rail with a Phillips #2 screwdriver or the HK sight tool (Fig. 5 & 6). Do not over tighten the screws. Fig. 8 – Clamping Screw (to tighten turn clockwise) Fig. 5 – Front Diopter Sight Fig.
Fig. 12 – Folding (lowering) TROY front sight Fig. 13 – Lowered sight TROY front sights INSTALLING Troy REAR Sights 1. The rear TROY sight installs similar to the front sights. Unscrew clamping assembly and place the sights at the desired location on the Picatinny rail. 2. To raise the sight, grasp and pull up until the sights locks in the upright position. To fold (lower) the sight, depress the button on the left side of the base and fold down. (Fig. 14-16) Fig. 14 – Rear Sight Fig.
Fig. 23 Fig. 24 Fig. 25 A wide variety of mechanical, optical, telescopic sights and accessories can be installed directly on the upper MIL-STD-1913 rail (example, Fig. 25), either on the upper receiver portion of the rail or on the four quadrants of the Free Floating Rail System. For sight alignment and zeroing, follow the instructions of the scope manufacturers. NOTE: Do not overtighten scopes, aimers, or any other accessories mounted on any of the MIL-STD-1913 (Picatinny) rail surfaces of the MR762A1.
Section 5 — Ammunition By using ammunition with match bullets or other match grade ammunition the MR762A1 will achieve the best level of accuracy. Use ammunition of the appropriate caliber and of recent manufacture. The MR762A1 is chambered for 7.62 x 51 mm ammunition and will functioned safely and reliably with most high quality 7.62 x 51 mm and Caliber .308 Winchester ammunition. NOTE: Use only high quality 7.62 x 51 mm NATO or Caliber .308 Winchester ammunition in the MR762A1 rifle.
NOTE: The magazine may be loaded into the weapon with the bolt assembly open or closed. The procedure listed below is for the bolt open. LOADING Loading the MR762A1 rifle for firing 1. Place the selector lever in the SAFE position. Point the muzzle in a safe direction with the trigger finger off the trigger and outside the trigger guard. 2. Pull the charging handle rearward to open the bolt and lock it to the rear by pressing the bottom part of the bolt catch (Fig. 29). Fig.
Confirm the weapon is clear and on SAFE before performing the following procedures. Failure to follow these warnings may cause injury or death to personnel. CAUTION: Never ride the charging handle forward. Allow it to move forward under its own power. NOTE: Close the ejection port cover if the weapon is not to be immediately fired. FIRING THE Rifle 1. Place the selector lever on SEMI-AUTOMATIC. 2.
b. Insert the small tip of the disassembly tool into the spring loaded detent located in the center of the rear takedown pin. Push the disassembly tool from left to right until the takedown pin reaches its limit of lateral travel (Fig. 35, 36). Fig. 39 – Drift out the Firing Pin Retaining Pin and lift up on the Drop Safety Fig. 35 – Takedown Pins Fig. 36 – Takedown Pin Detail WARNING: Always use the disassembly tool to disengage the detents on both the rear takedown pin and the front pivot pin.
WARNING: The retaining screws for the Free Floating Rail System (FFRS) handguard are held captive by small shaped springs located on the lower right hand side of the handguard. Attempting to completely remove the retaining screw could lead to damage of the handguard, shaped springs, and/or retaining screws. Fig. 42 – Slide the Bolt Head out g. Further disassembly of the bolt head, including removal of the extractor is not recommended (Fig. 43). Fig.
5. Lower Receiver: Reassembly (Assembly) of the MR762A1 NOTE: Always ensure the hammer is in the cocked position (down) before attempting to remove the buffer and action spring. Tools Needed: MR762A1 Disassembly Tool (located in the Buttstock), 5mm Allen Wrench, Small Straight Slot Screwdriver a. Depress the buffer detent with the tip of the piston rod and remove the buffer and action spring from the receiver extension (buffer tube) (Fig. 48). 1. Lower Receiver: a.
d. Ensure that the hammer is in the down (cocked) position before attempting to install the buffer and action spring. Mount the action spring onto the buffer and insert the buffer and spring into the receiver extension. Push back on the buffer far enough until the buffer is retained by the spring loaded buffer detent (Fig. 53). 3. Bolt Assembly: 2. Upper Receiver: a. Install the gas piston into the back of the gas block. The piston rings need not be staggered prior to installation (Fig. 54). Fig.
b. Insert the cam pin into the shaft of the bolt carrier, ensuring that the hole for the firing pin on the cam pin is aligned with the firing pin tunnels on both the bolt head and bolt carrier (Fig. 59). Fig. 59 – Bolt Carrier reassembly c. Ensure that the captive firing pin retaining pin is drifted completely out to the left hand side of the bolt carrier.
d. Insert the small tip of the disassembly tool into the spring loaded detent located in the center of the rear pivot pin. While pushing on the disassembly tool, drift the pivot pin from right to left until the pivot pin reaches its limit of lateral travel. The tip of the pivot pin should be visible on the left hand side of the lower receiver (Fig. 66). Fig. 63 – Installing the bolt assembly into the upper receiver h.
FUNCTION CHECK Magazine disassembly WARNING: Always ensure the MR762A1 is unloaded prior to attempting to perform a function check. CAUTION: Parts are under considerable spring pressure. Wear safety goggles and point the base of the magazine housing in a safe direction when disassembling or assembling. Read the complete procedure before attempting to disassemble the magazine. NOTE: The MR762A1’s selector lever can be placed on safe regardless of the position of the hammer.
Assembly (HK magazine) To assemble the magazine, use the reverse sequence used for disassembly. If magazine was cleaned, ensure that it is properly lubricated prior to assembly. Attach the follower and locking plate to the spring and slide the follower into the magazine housing (it will only assemble in one direction, do not force it). Push the locking plate down into the housing enough so that the floorplate can be slid back onto the magazine housing.
Lubrication All firearms require proper lubrication to function as designed and the MR762A1 is no exception. Absence of lubrication may impede the operation of the MR762A1, particularly in load-bearing or friction contact areas. Excessive lubrication may also cause function problems by acting as a magnet for dirt, grit, sand, and fouling. Many high quality, medium weight lubricants (oils) specifically designed for use on firearms, including those cited earlier will work well on the MR762A1.
Cleaning may be completed using dry cleaning solvent, bore cleaner, wiping with a cloth or an all purpose nylon brush. Using these guidelines will determine which applies. Cleaning materials are pipe cleaners, swabs, all purpose nylon brush and rags. NOTE: If cleaning is completed using a solvent, then a coat of lubricant must be applied for protection against rust and the elements. Dry cleaning solvent may be used to completely remove lubricants.
Inspection A visual inspection is recommended each and every time you clean a magazine, the magazine is disassembled, or a problem exists that could be magazine related. The following are guidelines that can help in identifying and solving magazine related problems. Many problems are very often related to incorrect operator use or maintenance, faulty ammunition and/or problems in the weapon. These areas should be checked for problems at the same time the magazine is inspected.
Section 9 — Troubleshooting Problems and repair This section contains operator level troubleshooting information for locating and correcting most of the operating troubles which may develop in the MR762A1 Series. Each malfunction for the individual part or assembly is followed by a list of tests or inspections which will help you to determine the corrective actions in the order listed. This manual cannot list all malfunctions that may occur, or all tests or inspections and corrective actions.
Section 10 — Exploded diagram and parts list 50 51
Parts List (for exploded diagram, pages 50-51) Item Description Part Number MR762 A1 (Item 1 - 101) — Upper receiver, compl. (Item 1 - 19) — Barrel MR762 16.5’’, compl. (Item 1 - 5) 1 Flash hider, compl. 2 Gas block 3 Clamping sleeve for gas block (2x) 4 Barrel nut 5 Barrel MR762 16.5’’, assembled 6 Gas piston, compl. 7 Rod, compl. 8 Upper receiver, assembled 9 Axle for cover 10 Ejection port cover, compl.
Firearm Type ________________ Serial Number ________________ Firearm Type ________________ Serial Number ________________ Number of Cumulative Total Maintenance Date Rounds Fired of Rounds Fired Users Name & Remarks ________________________________________________________________________________ Number of Cumulative Total Maintenance Date Rounds Fired of Rounds Fired Users Name & Remarks ________________________________________________________________________________ ________________________
HK USA-708144-04312014 HECKLER & KOCH 5675 Transport Boulevard Columbus, Georgia 31907 United States of America Tel: (706) 568-1906 Fax: (706) 568-9151 USA Website: www.hk-usa.com HECKLER & KOCH D-78722 Oberndorf/Neckar Postfach 1329 Germany Tel: 011-49-7423/79-0 Fax: 011-49-7423/2280 Global Website: www.heckler-koch.
