Heckler&Koch MR762A1 User Manual

Page 16

5. Lower Receiver:

NOTE: Always ensure the hammer is in the cocked position (down) before attempting

to remove the buffer and action spring.

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).

Fig. 48 – Removing Buffer Assembly

b. Check to ensure that the buttstock tightening screw is loose before attempting

to remove the buttstock. If tight, insert the large tip (3mm hex) of the MR762A1

Disassembly Tool into the tightening screw and rotate (but do not completely

remove) counter clockwise (Fig. 49). For cleaning and general maintenance

purposes, it is not necessary to remove the buttstock.

Fig. 49 – Buttstock Tightening Screw

c. To remove the buttstock, simultaneously depress the back of the buttstock release

lever while pulling downwards on the front lip. Slide the buttstock off the receiver

extension.

Fig. 50 – Removing Buttstock

The MR762A1 is now operator disassembled (field stripped).

NOTE: Disassembly beyond the above field stripping procedures should only be

undertaken by HK certified personnel.

REASSEMBLY (ASSEMBLY) OF THE MR762A1

Tools Needed: MR762A1 Disassembly Tool (located in the Buttstock), 5mm Allen Wrench,

Small Straight Slot Screwdriver

1. Lower Receiver:

a. Check to ensure that the buttstock tightening screw is loose before attempting

to install the buttstock. If tight, insert the large tip (3mm hex) of the MR762A1

Disassembly Tool into the tightening screw and rotate (but do not completely remove)

counter clockwise.

b. Two small set screws are located on the bottom of the receiver extension (buffer

tube). These set screws are provided to eliminate any play that may develop

between the buttstock and the extension. The left hand side of the set screw

features a detent surface that engages the buttstock. The right hand surface

features a cut to accommodate a small straight slot screwdriver. Rotating the set

screws clockwise will tighten the detents to the buttstock; rotating the setscrew

counter clockwise will loosen the buttstock. Using a straight slot screwdriver, rotate

the set screws clockwise using quarter turns and adjust until the detents engage the

buttstock but do not hinder removal or installation (Fig. 51)

Fig. 51 – Buttstock reassembly

c. Depress the back of the buttstock release lever allowing the front tab to pivot

downwards. Pull down on the front tab until the locking pin is not visible inside

the buttstock. Mount the buttstock onto the receiver extension. The buttstock is

adjustable for length of pull, with five different settings available to the operator.

WARNING: Ensure that only the proprietary HK buffer and recoil spring (action

spring) are installed in the MR762A1. Use of non HK buffers and recoil springs could

result in cycling problems and affect the reliability of the MR762A1 (Fig. 52).

Fig. 52 – HK MR762A1 Proprietary Buffer Fig. 53 – Installing buffer & action spring