Ithaca 12 ga barrel

[sugarcreekbrass]

My dad sent me the pics below of his barrel from his Ithaca Deerslayer. Other than it is a smoothbore slug barrel, I don't know specifics of the gun. He bought the gun used probably 30 yrs ago. He's never had any issues and has shot a lot of deer with it. He shot the gun 4 times on Friday just to check the scope. It was fine. Yesterday morning he took 3 shots at two different does and missed. The farthest shot was about 50 yds. Last night he swabbed the barrel and wiped down the gun because they were in the rain yesterday. This evening he shot at a buck and missed twice. After the second shot he noticed his barrel. The barrel wasn't obstructed. Any ideas what could have caused this. Thanks!

 

[Bigtanker]

I'm wondering if it was ammo related?

 

[sugarcreekbrass]

Unless it was a bad shell or box because it is the same Winchester slugs he has always used. I wondered if it could have had something like a stress fracture that finally gave out.

 

[rosejm]

The inside of the barrel, in the second pic looks interesting. Slightly out-of-focus, so it's tough to tell...

Looks kinda suspicious, as if there could have been an obstruction caused by the first shot, which the second cleared (violently).
No scale for reference, but that seems like the right amount of distance between the marks inside & the start of the bulge for a second slug.

 

[Bigtanker]

The inside of the barrel, in the second pic looks interesting. Slightly out-of-focus, so it's tough to tell...

Looks kinda suspicious, as if there could have been an obstruction on that first shot, which the second cleared.
No scale for reference, but that seems like the right amount of distance between the marks inside & the start of the bulge for a second slug.

I see what you are talking about. The line inside the barrel looks to be the giveaway.

 

[sugarcreekbrass]

I see what you are talking about. I just don't know what the obstruction was because he swabbed the barrel the night before and didn't leave anything in it. He didn't fall or drop the gun that would have put dirt in it. He did say that he held it vertically with the butt on the stand platform for a bit. Unless an acorn dropped and was lodged in there I don't know what it could have been. He said the shots felt and sounded normal, kicking like a mule, so I ruled out a squib. His cousin knows a guy that is a machinist and has done a lot of barrel work. We are going to have him take a look at it. Thanks!