Just noticed my stock Stag 6H 223 upper (Hogue handguard, stainless bull barrel, low profile gas block) is throwing some carbon around the gas tube from the gas block (see pics). The rifle has about 300 rounds through it and I haven't noticed this before but won't say it's impossible that I've missed this a few cleanings since it's almost under the handguard. The tube is pinned in the gas block and neither appear to have moved since manufacture. Love this rifle, and it shoots one-hole groups despite this. How big of an issue is this? I've never run into it but assume the gas tube will erode there and the problem may get worse? Is there an easy fix without replacing the gas block and tube?