Here are a couple of gas port pictures to give you a sense of what is common. I don't have a 6ARC so these are different calibers.
Proof 6.5G, roughly 2k rounds, uncleaned. The erosion is filled with carbon. This barrel shoots, does not drift or string:
View attachment 8402219
WOA Wilson 223Rem. 2.5k rounds, uncleaned:
View attachment 8402220
Brand New Faxxon 5.56. Notice the tooling marks, they run the entire barrel.
View attachment 8402221
Even the Faxxon port is round and unchamfered.