Posted: 8/22/2015 11:03:22 PM EDT
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I bought 2 SOCOM barrels that are supposedly surplus items. One has a gray FSB. The other one is the color of the barrel, which is more typical in my experience. Any insights?
Top barrel (gray FSB) is dated 2010. The bottom one is dated 2011. 
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Different types of parkerizing, or possibly different hardness of the base metal.
It looks like top FSB is zinc phosphate coated (known for a lighter tint of grey), bottom FSB is manganese phosphate coated (known for a darker charcoal appearance). Being surplus, it's possible (and likely) someone swapped the FSB at some point. I haven't seen anything factory Colt with zinc phosphate in a LONG time. |
| I posted that very question here years ago and got no answers. I have a 6920 with the same light colored front sight base. It has a law enforcement only marked lower on the right side and I bought it brand new so it came that way from Colt. As someone that does his own parkerizing it's not zinc parked. When maganese park starts to get weak(needs replaced), the parts start to come out light grey. I think that is the case with these light front sight bases from Colt. |