Heckler&Koch MR556A1 - Manual (Page 22)

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3. Apply a medium coat of lubricant to the extractor (Fig. 70).
4. Apply a heavy 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.
Fig. 71 – Lubrication of MR556A1 Charging Handle
5. Apply a medium coat of lubricant to the interior and exterior surfaces of the charging
handle (Fig. 71).
LOWER RECEIvER ASSEMBLY (FIG. 72 & 73)
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 MR556A1 Lower Receiver Assembly
Fig. 73 – MR556A1 Buttstock Assembly
Fig. 74 – MR556A1 Lubricant Guide
LUBRICATION SUMMARY
NO Lubrication: (surface is dry and not slippery to the touch)
• Plastic or rubber components
• Sling webbing
• Optics
LUBRICATION
• Gas Piston and Gas Cylinder,
• Buffer and recoil spring
• Bolt, Bolt carrier, Cam pin and Firing Pin Safety
• Extractor
• Ejector
• Barrel extension
• Bore, chamber, locking surfaces of the chamber and bolt lugs
• Receiver take down and pivot pin
• Hammer, trigger, disconnector springs and selector lever in trigger group
• Piston rod
• All metal parts and/or any area where metal contacts metal.