What is this ring at the top of the neck?

TNBillyEarl

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Jan 31, 2021
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Deer season ended yesterday. Tonight I was cleaning 7mmRM brass (R-P, 5+x fired) and about half the rounds had these small grooves/rings around the top of the neck. What is it? My resizer? A chamber (T3x) that has something odd cut in or out? Please advise...

B

20230109_202032.jpg
 
Tell you what the kinda looks like to me...

Someone trimmed them with a dull or poor trimmer...
Didn't de-burr them...

Then they got shot and sized a few times...
And that material just sort of smashed itself together on there
 
Tell you what the kinda looks like to me...

Someone trimmed them with a dull or poor trimmer...
Didn't de-burr them...

Then they got shot and sized a few times...
And that material just sort of smashed itself together on there
That was my first thought, but the ring/impression is not close enough to the top of the throat. I always trim, chamfer, and de-burr b/t firings. My guess is that some of the Core-Lokts were crimped and some were not. Again, many thanks to all for weighing in.

B
 
That was my first thought, but the ring/impression is not close enough to the top of the throat. I always trim, chamfer, and de-burr b/t firings. My guess is that some of the Core-Lokts were crimped and some were not. Again, many thanks to all for weighing in.

B
I politely disagree...and just know my tone isn't malicious. That isn't some crimped and some weren't. If I had 10 million dollars I'd bet 9.5 it's not that but rather more an issue with what I suggested.( i could be poor then..lol) I'll explain...
What I suggested might not be the exact issue...and I do believe what you say about trimming, deburring...etc...

Please look at the case to the right. What do you see?

I see a case mouth that is going from 8 o'clock to 2 o"clock

Look at the case all the way to the left. It's going from
3:30/4 o'clock to 10 o'clock

I bet the contestant in the middle is rotated and we are only seeing the high side of the case mouth.

Now the explain...

I had cases that were just like yours.

What was going on was my son was using the rcbs prep center and literally used king kong force on the O.D. chamfer tool tool and the ID chamfer tool as well.
The OD tool was particularly the issue. Too much force at just a slight offset resulted in case mouths EXACTLY like you have.Screenshot_20230110_120703_Chrome~2.jpg
 
Last edited:
It’s a crimp. That rectangular high spot is where the fingers in the collet squeeze together and “pinch” the brass. You see the same thing with the Lee factory crimp die.
 

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It’s a crimp. That rectangular high spot is where the fingers in the collet squeeze together and “pinch” the brass. You see the same thing with the Lee factory crimp die.
Can you post a picture of what you speak of? I'm certainly not arguing with you but something isn't adding up here...

Look at the case mouths
The book end cases #1 & #3 are slanted...

Moreover above the OP stated these were fired 5+ times..
And in his response to me he stated he sizes, trims, and de-burrs each one...every single time

Taking his word as good how is that trimmed 5 times, deburred 5 times, chamfered 5 times etc...
And all this material sitting there plus wasn't noticed prior?
 
Thanks for some more thoughts on this. So, the pic is misleading. I even thought about not posting it last night and taking a different photo this morn. The camera on my phone does make the right case look slanted, and slightly on the left case. But they aren't. (I don't want to start another question/post on optics and close angles, but my lens was super close to the middle case.) I use hand tools (Lyman) to trim, chamfer, and deburr; and if I ever had any case look like the one above I would know. I think I took this pic after trimming but before the chamfer. This past year I bought some once fired R-P brass and mixed them in with my own once fired Core-Lokts that I found in a drawer from way back (I had to go shoot them first). I then just randomly picked 50 pieces and used that as my batch for my Tikka. (For the past year I have experimented with different cases, powders, and bullets -- R-P cases always made for more consistent groups.)

Disclaimer - I don't know much and haven't been after this for very long. I greatly appreciate all the input and insight from this community.

B
 
And all this material sitting there plus wasn't noticed prior?
My apologies - yes I have noticed it prior but never got around to asking about it. I've learned I need to be much more precise with my problems on here. (There's a joke somewhere in there...) -B
 
My apologies - yes I have noticed it prior but never got around to asking about it. I've learned I need to be much more precise with my problems on here. (There's a joke somewhere in there...) -B
Did you notice your case mouths aren't remotely square
 
Here's a couple of pics. I hope the first one shows that the mouth is square and that the camera makes things look askew (note the base looking curved). Moreover, the second pic. In my bottom drawer I found some 220g .30-06 Core-Lokts from years back. They show the crimp pretty well. Again, thanks.
-B

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Here's a couple of pics. I hope the first one shows that the mouth is square and that the camera makes things look askew (note the base looking curved). Moreover, the second pic. In my bottom drawer I found some 220g .30-06 Core-Lokts from years back. They show the crimp pretty well. Again, thanks.
-B

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Issue resolved. 👍
 
Deer season ended yesterday. Tonight I was cleaning 7mmRM brass (R-P, 5+x fired) and about half the rounds had these small grooves/rings around the top of the neck. What is it? My resizer? A chamber (T3x) that has something odd cut in or out? Please advise...

B

View attachment 18776
Late to this discussion, but that looks just like factory crimped ammo, and just like the crimp applied by the Lee Factory Crimp Die. BTW, that Lee die is really good for lever-action rifle cartridges.

Regards, Guy
 
Did you notice your case mouths aren't remotely square
I noticed that the horse is dead. It drank way too much water while it was hot and foundered, dead. When I say dead, man I mean that horse stepped in a gopher hole and had to be put down dead. When I say dead I mean buzzards are fighting coyotes for butholes and eyeballs dead. :ROFLMAO:

It’s what remains of a Remington factory crimp. It will disappear after a couple 2-3 firings. Y’all have fun (y)
 
Late to this discussion, but that looks just like factory crimped ammo, and just like the crimp applied by the Lee Factory Crimp Die. BTW, that Lee die is really good for lever-action rifle cartridges.

Regards, Guy
Tube fed lever-action rifles. :)
 
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