Rusty spot up inside my Browning A-bolt Micro Hunter 22 Hornet?

[wahoowad]

Groundhog season is upon us so I was giving my A-bolt 22 Hornet a cleaning in anticipation of a range day tomorrow to check my zero. First patch came out surprisingly dirty and rusty looking, and with subsequent patches I was feeling a rough spot an inch or two up into the throat. I always use my bore guide, so whatever I was feeling was about 2 inches past that.

It smoothed out some after hitting it with a bronze bore brush but I can still feel the patch sliding past something rougher than the rest of the bore. I assume it just developed a rusty spot somehow although thought I had always babied this sweet little shooter.

Gun is a 2010 model and I only have 120 shots down it. I'm just gonna shoot it tomorrow and see how it does, I usually don't clean it after zeroing for the season unless it sees really heavy use. Any suggestions on how to address it?