New GM .62cal Flint smoothbore barrel arrived today...always amazed by the amount of flash rust in a new factory barrel from GM...30 minutes with many wet WD40 patches and alternating passes of a bronze bore brush in a drill motor...and the orange colored patches gradually changed to machine oil black, then gray, then finally clean...will hit it again tomorrow night to be sure its stabilized...a lot of value for the clearance sale price of $100 !