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Posted: 8/27/2010 10:32:57 PM EDT
I was looking through the EE and came across a 10.5" LMT DI upper with 120 rounds through it. It has a unusuall wear pattern inside the upper. What would cause this? |
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Very minor machining artifact, the uppers are also forged from solid, the bolt carrier path is a deep drilling operation, looks like they didn't clean it up fully but that is just a fraction of a thousandth of an inch. After hard anodizing and sealing, the internals of the upper are coated with a moly dilsulfide dry film lubricant. This has worn off the receiver. This is added because hard anodizing is harder than the 8620 alloy steel of the carrier and when new, it is quite abrasive. The dry film lubricant reduces carrier wear. It is nearly impossible to remove dry film lube with solvents in normal cleaning. You could refinish it as the products are available in rattle cans. Take the upper apart, pull the barrel and clean the interior with acetone. Rough up with Scotch Brite and apply the dry film lubricant. Let cure for a week before installing. |
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