New CHF 5.56 Barrel Defects

USNIGHTGUNNER

Sergeant of the Hide
Full Member
Minuteman
Dec 8, 2009
266
71
The Woodlands, TX
What causes this?

This is a new CHF barrel, and this is just a sampling of the screenshots that I have on this barrel. Not pretty!!!
Screenshot 2023-11-22 at 1.18.30 PM.jpg
Screenshot 2023-11-22 at 1.20.41 PM.jpg
Screenshot 2023-11-22 at 1.21.02 PM.jpg
Screenshot 2023-11-22 at 1.21.41 PM.jpg
 
I consulted with a good friend on this that has over 25 yrs experience building ARs, and I quote

"I’ve seen this a lot in (a particular manufacturer) CHF barrels. It’s sort of a copper colored substance that follows the contours of the lands and grooves.

I’ve speculated that it is some sort of leftover release agent or jacket material from proof loads. Hitting it hard with JB Bore Paste or KG-2 will not only remove it, but will ready the barrel for running super clean and accurate without wasting a round."