Tatted brass?

B

Big Caliber

New member
I never really thought about it over the years, but why do some brands of pistol brass have a tiny "engraved" dotted ring around the case roughly 1/4" down from the mouth?
 
When sorting cases the knurled line around the case become another way to sort cases. My favorite head stamp is military, for every manufacturer I add another year when sorting.

F. Guffey
 
it's called a cannelure

45ACP.jpg
 
I think the really faint ones are a purely cosmetic artifact from a time when a much deeper version actually had a purpose. That purpose was to keep the bullet securely in place so as to not slide deeper in the case. Using the 44-40 as an example, with an original black-powder load, the powder would have been well compressed and it wouldn't have been an issue. However, with the transition to smokeless powder, and with bullets that were crimped over the ogive, that is, lacking a crimping groove, and being used in a tube-magazine rifle, then with the recoil of each shot fired, the remaining cartridges in the magazine would certainly have their bullets progressively hammered deeper until something bad happened. Placing a prominent cannelure on the brass cases at the base of the bullets was one way of dealing with that problem. In more recent times, using a bullet with a pronounced crimp-groove and an adequate crimp has been a more common way of dealing with the situation. Autopistols are another situation where the somewhat violent action of driving a fresh round into the chamber can hammer bullets deeper and raise pressures to dangerous levels. Revolvers don't have that issue. There is much more that could be said on this subject, but in the interest of brevity, I will leave it at that and let others chime in on some of the other aspects of it as it applies to various arms and ammunition where this has been used.
 
Something I've noted is that the practice is diminished. It costs money to add them.

Many bullets have them as well, and plenty of others don't. I think that rifle bullets are going are going to continue the trend of obsolescence.
 
I never really thought about it over the years, but why do some brands of pistol brass have a tiny "engraved" dotted ring around the case roughly 1/4" down from the mouth?
Click to expand...

And then consideration should be given to the possibility the Tatted brass? Line is a knurl. A knurl is another way to raise the surface, reduce the inside diameter or increase the outside diameter etc. I know, most are so confused but if I thought my cases were fitting the chamber with room to spare I am one of the few that could tighten the case in the chamber by knurling the outside of the case.

Then there is that moment when the pressure hits the inside of the case and flattens the knurl.

Again, the knurl on a case aids is sorting cases after the case has been fired.

F. Guffey
 
Wil Terry, yes, you read that correctly, all I did was cut and paste. The title of this thread is "Tatted brass". I have knurling equipment, some of it by knurling standards is not recognized as a tools for knurling. There are times I want to increase the height; when increasing the height the Navy (at one time) called that method 'gluping'.

You are not going to believe it but there was a time the Navy had 'gulpe makers'. Again, the outside diameter was increased by knurling and the inside diameter can be reduce by knurling. And then there is reaming after knurling when fitting for close tolerances.

F. Guffey
 
The faintest ones I've seen were on M852 brass, down at the head. The only purpose was to give a quick visual indication that the ammo was not authorized for combat (at the time; would be now).

A lot of the early ones were a completed circular ring around the brass and had no knurl pattern. Those were stops for lubricated lead bullets, something you can often push into a straight case with your thumb. With jacketed bullets it doesn't appear to serve a purpose, though.
 
I've always been told (anecdotal, I know) that the cannelure in the brass is still sometimes used because of how the factory loads - it still serves as a bullet stop, but not necessarily for the purpose of keeping the bullet from telescoping in during the firing, but rather because of the equipment used to load at the factory. It also helps to identify different loadings or projectile weights because the brass cannelure will be at the base of the projectile.

After a reload or two any change in diameter of the brass at the cannelure is gone anyway, it's strictly for factory loading purposes.
 
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