What's causing this line during resizing?

[cwuwildcat]

I'm making my first run at using my rock chucker, and am getting a line all the way around the base, about 1/4 inch up from the rim.  What's causing this, and is it a problem?  It's faint, but you can barely feel a slight ridge when you run a fingernail across it.  I've ran 8 or 9 through, and they all get it.  The case is fitting all the way into the die.  Is there an adjustment to the die that needs to be done?

[high country]

is the shell holder is bottoming out on the die? if not that would be my first guess. what are you using for lube?

[cwuwildcat]

HC,

I'm using RCBS case lube-2, and the shell holder is bottoming out.  I've put in the die, raised the ram until the case holder hits the bottom of the die, lower the ram and tighten the die another 1/4 turn.  I've even turned it another 1/4 turn to make sure, and it still leaves that ring.   

[haugenna]

That line is from the lube you are using, working the brass, and that is where the shell hold hits he base of the die.

Do they fit in the chamber?

If they fit loosely, don't worry about it.

[bobcat]

Try just sizing the necks. Your brass will last longer that way. Works fine as long as you're only using them in one rifle.

[JackOfAllTrades]

Yes, agree.. That line is normal. There isn't a die that resizes the 'whole' case to the rim. That's where the case gets the thickest anyway and doesn't expand much -if any at all. As long as your die just barely hits the shell holder at full stroke, you're golden. Now, if you start seeing some dimples at the case shoulder up toward the neck, then either back the die out 1/8 turn at a time until you don't get any dimples there. Too much case lube can do this too.

I'd like to see a broadside photo of that whole case please...

While Bobcat is correct, I'll advise that all new reloaders should full length resize until they've got the hang of things.

-Steve

[Ray]

Looks normal to me.

[FALFire]

Yep, it's normal. Just be sure you are full length sizing if you are loading for any semi auto gun like an AR-15.

[Jamieb]

The ring is normal. Where your seeing the ring around the case is where the spot a case expands the most when fired and also gets sized back. If you see that line getting wider then its time to start looking for case wall thinning there. You check this with a thin peice of wire bent( paperclip), run the wire up and down the inside of the brass. If its starting to get thin, you'll feel it as you drag the tip of the wire accross. Thats where a case comes apart in a case head separation. The reason the brass thins out in this spot is when a fired "expanded case" is resized in a sizeing die the brass is pushed forward, causeing the case length to grow.
I know I'm not very good at typeing out an explanation so if that isnt clear, look up case head separation, the speer manual has good pictures.

[Jamieb]

Heres a picture of a 300 RUM and a 22-250 case.

[Jamieb]

Heres a picture of a 300 RUM case cut in half, this brass had 7 fireings on it and I cut it just to see what it looked like inside.
You can see the ring around the outside, no thinning of the brass though.

[MtnMuley]

Wow Jamie.  That's great with 7 firings from a rum.  What kind of brass and how many grains were used?

[Jamieb]

Rem. brass as thats all I can get for a RUM. The load is 95.5 gr. of Retumbo under a 200gr accubond for 3150fps

[cwuwildcat]

Thanks for all the answers, and they completely make sense.  The cut away is cool too.  I love seeing the guts of something that you kind of take for granted. 

In a round-a-bout way, they answer another question I had about the "small based" dies.  For my 30.06, I'm using the RCBS full length die, and I bought the RCBS full length "small based" dies for my .223.  When I first sized my .06 and got these lines, I wondered if it was something I was doing, the die, the way it's supposed to be, etc...  I work as an application analyst in an IS department, and the joke is that "you cant spell analyst without the ANAL".  I threw in the .223 dies and sized a few, and they didn't have the line, or it was at least a lot closer to the rim.  That's what triggered my concern about the .06 die.  I think the small based dies size further down the body of the case, to make it alittle smaller, so that they cycle through a semi-auto easier.  Hence the name "small base", maybe?

[high country]

small base dies are sizing the case smaller then standard dies, thus allowing easy feeding in the autoloaders. once you get to the case head, there is no resizing it., if you stretch it, primers don't stay.......and you prolly paid hell getting the bolt open.