I just got a used Noveske Afghan upper from a fellow shooter. The upper is clean and normal except that there are burn marks before and after the gas block. That’s an indicator for gas leakage, right? It’s quite obvious on the stainless finish. There are two pictures after I tried to swab the marks off.
After the gas block
Before the gas block
What should I do?
Shoot it more.
Those aren’t burn marks. That is carbon build up, and the white flaky shit is oxidized copper. Shoot the gun more.
One thing to add, carbon fouling does tend to be more visible on stainless barrels. If you really want to, you can try to clean it up a bit.
If the rifles working fine, I wouldn’t worry about it. The more you shoot, the less “leakage” there will be, they tend to self seal over time.
You can always re-bead blast the barrel if it really bothers you.
You will notice this much more on stainless barrels. Unless duracoated/gun-kote or something like that its just going to show up more.
Some poeple bed the gas block on with Loctite, but even then you may get a slight amout on gas escaping.