What's the deal with the line on the side of mil 45 acp?

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black_hog_down

New member
This is Olin 45 acp. Got it from an estate sale. What's the deal with the line on the side and can it be reloaded? Thanks.
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It's called a cannelure, and it's intended to prevent the bullet from being pressed further into the case. Has no effect on reloadability.
 
Actually, a cannelure is a groove line around any cylindrical object -- be it bullet or case in this instance.

Since an autoloading pistol cannot be roll-crimped, the crimp to prevent bullet setback is a cannelure in the case to form a slight shelf at the bullet's base.
 
IIRC, the root word for cannelure is an old word meaning channel, so you could put a cannelure in a wood dowel rod if you wanted to, though, in non-firearm terminology it usually means a length-wise groove in a rod or cylinder or column. Incidentally, the exactor groove in a case is also sometimes called a cannelure (see the glossary on SAAMI's site).
 
^Yep^ Not a dedicated reloading term. It just means an imprinted groove around a cylindrical object. Possible an old machining term? :confused:
 
Not sure what it means but i have reloaded 9mm cases with this no issue.
Click to expand...

Same here. I run into those from time to time in 9mm. I thought they were decorative! ;) So I learned something.
 
Yes. That kind of brass cannelure doesn't thin the brass enough to cause a problem because it is located where the brass expands against the chamber for support. Pressing against the side of the chamber will tend to iron that cannelure out, so it loses its functionality after the first pass, but does not harm.
 
The cannelure on the case at the base of the bullet also helps to keep the bullet from being driven back in auto loading weapons.
The round headspaces on the mouth so you can't put a heavy crimp there...sort of a back up to a taper crimp.

I thought I was looking at a vertical crack in the side of the case but it could be the lighting....look at the case just above his ring , appears to run from the extractor cut to just above the cannelure . Anyone else see that ?
 
gwpercle said:
The cannelure on the case at the base of the bullet also helps to keep the bullet from being driven back in auto loading weapons.
The round headspaces on the mouth so you can't put a heavy crimp there...sort of a back up to a taper crimp.

I thought I was looking at a vertical crack in the side of the case but it could be the lighting....look at the case just above his ring , appears to run from the extractor cut to just above the cannelure . Anyone else see that ?
Click to expand...
I see it. Just a reflection I think.
They are new unfired rounds.
 
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