funny ring on .223 cases

[foreign]

im getting these funny rings of more material on my .223 brass. its forming where you would normally get the thinning out of a case just buy the head. ive cut several brass in half length ways and its not thinning on the inside. wondering if anyone might know what this is is from or have had it before. im not full length resizing but am using a full length die.
cheer

 

[Natty Bumpo]

If I understand you correctly, I notice a similar ring on some of my cases. I've poked around in there with a bent paper clip but can't feel any evidence of separation. I've come to the conclusion that the ring is where the die "stops" when sizing the case. Even if you're not using a full length die to bump the shoulder back, maybe it still leaves that ring.

Anybody with more experience than I have an opinion?

 

[foreign]

hey natty thats what im thinking it is too. i defiantly cant fine any indication that is head separation either.,i just wonder how this extra material is effecting acuracy. is the ring on urs even the whole way round. its not on all of mine

 

[loaders_loft]

im not full length resizing but am using a full length die.

I think you just answered your own question...