Ring around brass?

[Guest]

Hi,

I have some 9mm brass that has a ring of dimples around it, about 1/4" from the case mouth.  It's very uniform, like it was rolled into the brass during manufacturing.  Anyone encountered this and know what it is?  Tried Google but no luck without knowing the correct terms to search for.  Thanks 

[Oh Shoot]

I have some off and on too, never remembered on which brands I've seen it. Always figgered it was just due to some crimping process used and never paid it any mind.

I don't reload, so dunno if it causes any extra difficulty in that regard?

- OS

[RED333]

It is called a "cannelure', keeps the bullet from getting pushed back into the case during recoil or other wise.

I have a the tool to do the job, http://www.bulletswage.com/hct-1.htm. 

Works on swaged bullets as well to make a crimp grove for the case mouth to grip to stop set back.

[noylj]

It can also be used internally by the manufacturer to identify certain loadings.

I have a lot of cases with two cannelures and one with three cannelures.

Sometimes you can "guess" that a .38 Spl case was used for wadcutter ammo as the cannelure about 3/4"  below the case mouth.

In jacketed bullets, a cannelure is for the case mouth to be rolled into for a roll crimp. Lead bullets have crimp grooves you can't miss.

 

Why are "what is this ring" questions suddenly popping up in so many forums?

Edited December 12, 2016 by noylj

[quedz]

This ^^^

[caorlann.macgregor]

On 12/11/2016 at 11:44 PM, noylj said:

.Why are "what is this ring" questions suddenly popping up in so many forums?

In my case it's because I hadn't seen it before and found a random single round in a box of range rounds.

[DeepSouth]

Aquila is the only 9mm cases I've found with the ring. I scrap all Aquila and Perfecta, 223/556 flash holes are off center. Don't want to find in their other calibers.