Maybe you should try cleaning it.....
Follow Up on the cleaning process:
So, after that post I spent 2 days scrubbing the gunk off the barrel and gas block and it looks "good as new".
Materials:
- 1 brass cleaning brush (small size)
- 1 plastic cleaning brush (small size)
- 1 aerosol cleaner/lubricant (CLP)
- 1 roll of paper towel
- 1 pair gloves (high recommended)
- 1 shop mask (old N90 lying around?)
Setup:
- find somewhere you can leave the rifle (or upper) muzzle down for a day or two
- layer a few pieces of paper towl on the floor to catch the drips
Steps:
1) spray CLP (or your preferred cleaner/lube) up on the outside the barrel (towards the receiver) and work your way down to the gas block
- goal here is to soak all the dirt and rust bits
2a) after sitting for an hour or so, take the brass brush and fit it between the bigger diamond slots scrubbing the barrel down from the receiver towards the gas block
2b) repeat this process 4 times: cleaning the barrel from the leftside at the top, left bottom, right top and right bottom
3) repeat step 1 and let it soak at least over night
4) repeat steps 2 with a small plastic brush
5) fold paper towel pieces to fit into the diamond slots and wipe down the barrel from the receiver to the gas block
After all this, I still had some super tiny rust spots on the block since it's got so many hidden angles, but pretty sure it's surface rust from dirt/debris. I've had 2 matches since and, now, I spray the barrel down right when I get home and let it sit muzzle down on paper towel over night to let the gunk drip down to the block. I'm too lazy to full clean the night after a match, so the next day I wipe down the barrel and gas block with paper towel and haven't seen another rust spot since.