Ring around the case

[biodsl]

I cleaned and re-set up my sizing die. Here's the same case as above after being sized.

Grendel Ring_first_sized.jpg

[Lemonaid]

The first time I saw that ring on my brass I was concerned it was evidence of incipient case head separation but that usually shows up after firing, not re-sizing and it is mostly not a perfect circle around the case plus is often about 1/4 inch above the sizing ring mark/case head.
I think happy nailed it with "sizing die trying to size the beginning of the solid case head"

[Klem]

Yep, that's the start of the solid web.

Here's another thought...if these cases have been previously fired then the web could be expanding in diameter with repeated hammering. While the web is expanding the die hasn't changed. This then shows up as more pronounced difference at the border of the solid web and thin wall.

[xjtony]

The last case of American Gunner I bought did that on almost every round. I've not seen any issues sizing or reloading the brass. None of the other brass I've had has shown this.

[biodsl]

The last case of American Gunner I bought did that on almost every round. I've not seen any issues sizing or reloading the brass. None of the other brass I've had has shown this.

That's interesting. I started using Hornady brass after I bought a couple 200 rd boxes of American Gunner. All my Hornady brass is AG brass.

I'm feeling much better about of all this now.

[xjtony]

Oddly none of the other hornaday brass I have (SST, black, or fresh cases have done it. Only the AG.

[Cereal Thriller]

All my hornady brass has it.

it is a very common sight in semi auto cases. Enough of the head has to remain out of the chamber, when the firing of the bullet occurs the shell is moving backwards to be ejected before the bullet leaves the barrel (at least on anything of typical barrel length). You still have pressure in the barrel and the walls of the brass at the point on the shell casing just barely takes a little puff before the shell is pulled clear of the chamber, bullet exits the barrel and pressures are gone. So when you resize you hit this spot and all is well again.


Glock had this issue with an unsupported chamber, would bulge out and leave a smile shape on the brass. Had people worried that if you reloaded the same shell over and over it could possibly cause a failure. I imagine it could if you put serious effort into reloading it and ensuring the shell chambered at the exact place each time.