[Gadzooks Mike]

Ok, here's a 30-30 shell with a bright, shiny ring around the case. I couldn't feel a coresponding "notch" on the inside, so I cut it open. And found nothing. So when does this shiny ring mean something? What am I looking at wrong?

[ReloaderFred]

This is pretty common with the .30-30, due to it's thin case. You're seeing more expansion in the thin portion of the case, and less where the base of the case thickens. My experience has been that .30-30 cases either split at the neck or the shoulder before incipient case head separation becomes an issue. That doesn't mean that you can't, or won't, have case head separation, but I've seen the other issues first.

Hope this helps.

Fred

[The Bushmaster]

If you are worried about case seperation on .30-30 cases. The first thing to watch for is if you are experiencing case stretching after resizing to the point that you have to trim them everytime you resize. and I don't mean justto getthem back to the same size as the shortest. I mean in access of a few thousands of an inch. Other then that...Fred has it...

[Gadzooks Mike]

No, actually I want to know why there is a ring there since there is no thinning of the brass at that point on the inside. Where'd the ring come from?

[R.W.Dale]

No, actually I want to know why there is a ring there since there is no thinning of the brass at that point on the inside. Where'd the ring come from?

I know I know! (raises hand)


I'll bet that ring is the same height as the cartridge separators for the ammo box you had them in. I know from personal experience that riding around in a vehicle the cartridge boxes themselves will rub a shiny spot around the case that looks suspiciously like a expansion ring

[Sport45]

I think that's where the sizing die looses contact. Below that point the case didn't expand.

[last to know]

my thought is a worn area in your chamber.

[Gadzooks Mike]

Ok, thanks! So I guess the first sign of impending head separation is a shiny ring around the case mouth. (I meant HEAD not MOUTH. See red circle in photo 1) Except not always. Bushmaster, I'll keep an eye on that trimming - that's at least something solid to work with. Thanks!

[ReloaderFred]

There won't be a shiny ring around the case mouth. What The Bushmaster is talking about is if the cases stretch an inordinate amount and you have to trim a lot off the case mouth to get them back to the proper length.

When cases stretch, the material comes from the area where the web and the case wall meet, or just above that point. The lengthening of the case pulls the brass up and makes it thin at that point, not the case mouth.

Hope this helps to clear it up for you.

Fred

[Gadzooks Mike]

ReloaderFred - yeah, I understood that. What was confusing me is I had a shiny ring without any thinning down there where I drew the red circle. I meant "head" not "mouth", sorry. Anyway, I'll ignore the shiny circle and worry more about the trimming requirements. See my confusion now? All of the advise I've seen here says when a shiny circle appears there around the HEAD, there is a thinning of the brass there and it will soon separate and the case should be disposed of. In this case, it doesn't seem to be true.

[P51D]

I think Sport45 might be on to something. That is, it might be where the sizing die loses contact.

P51D

[243winxb]

The shiny ring is much smaller, not as wide, and very bright. Your photo 1 with the red circle around it is from the chamber or die. This is what it will look like near the head or in the body. Had to get a good photo because is very thin. This photo is of a 223 rem case, inlarged. http://i338.photobucket.com/albums/n420/joe1944usa/caseseparation.jpg

[Walkalong]

That looks like a mark as well vs stretching, but like you say, it is tough to get good photos of subtle little things like that.

[bullseye308]

I'm gonna have to go with Sport45 on this one. Take a fresh piece of brass that doesn't have that ring on it and run it through your sizing die. See if it has that ring after(I think it will). I used to get that on 308 till I screwed the die in a little more.

[Gadzooks Mike]

Got it - thanks guys!