Heckler&Koch MR762A1 - Manual (Page 22)

42 43
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. Do not use lubricants that boast of
their ability to penetrate metal as these substances may deaden cartridge primers.
UPPER RECEIvER
Apply a light coat of a suitable lubricant to the interior of the upper receiver, bore and
chamber, barrel nut, outer surfaces of barrel, barrel nut, front sight, surfaces under
handguard and forward assist.
Fig. 69 – Lubrication of the MR762A1 Bolt Carrier Assembly
Fig. 70 – Lubrication of the Gas Piston, Piston Rod, and Barrel Nut Exterior
1. Apply a medium coat of lubricant on the gas piston and operating rod (Fig. 69)
2. Apply a light coat of lubricant to the extractor pin, the firing pin, firing pin spring, firing
pin recess in the bolt. Apply a a medium coat of lubricant to the red areas (Fig 70).
3. Apply a medium coat of lubricant to the extractor (Fig. 70).
4. Apply a light coat of lubricant to the exterior of the bolt carrier, outside of the firing
pin retaining pin, cam pin, and bolt head. Pay special attention to cam pin area inner
and outer surfaces of bolt carrier, anvil, and bolt head’s locking lug.
5. Apply a medium coat of lubricant to the interior and exterior surfaces of the charging
handle (Fig. 71).
Fig. 71 – Lubrication of MR762A1 Charging Handle
LOWER RECEIvER ASSEMBLY
1. Apply a light coat of lubricant to the exterior of the receiver and receiver extension
(buffer tube), interior of the exterior metallic surfaces, exposed pins, and magazine
springs.
2. Apply a medium coat of lubricant to takedown pins, pivot pins, detents, inside the
buffer extension tube, buffer detent pin, springs inside the lower receiver, trigger
mechanism, hammer, disconnector, and sear inside the lower receiver.
3. Apply a medium coat of lubricant on the (recoil) action spring, buffer.
Fig. 72 – Lubrication of MR762A1 Lower Receiver Assembly