It looks like a crack, but it isn't. It was just a build up of crud. I scraped it off and it is fine.

Thanks for all the info. Thanks again!
[Edited by John Dunkle - please become a Member. Thank you!]

You would be wise to buy a 20MM cannon brush and aggressively scrub the bores, wet with oil or solvent, and see what you have there.

my old 8 ga lifter i got from mills was in worser shape than this gun and it s shooting now...so with a little work and a little luck you can bring it back to shooter status with out spending too much if you do all the work your self.....main thing clean up barrels first to see if they will be safe to shoot them...charlie

That is exactly it Charlie. I have cleaned up a few ugly rust piles to find a great shooter underneath. The barrels are everything in that call.

There is a low limit to the amount of work and money you should spend on a grade 2 ten gauge. This is not an eight gauge.