07-20-2011, 09:52 PM
If these bolts have a kind of sheen to them, and are extremely hard on the surface, that is nitro-carburized, aka ion bond, aka Melonite, aka quench-polish-quench, gas induction, and so forth. Very tough metallurgy that blows chrome away really. You're looking at a Rockwell hardness of 65-70 usually from what they normally get with those treatments.
The barrels I have that are nitro-carb'd will take a metal file like water off a duck's back.
The barrels I have that are nitro-carb'd will take a metal file like water off a duck's back.