Is it put there by the manufacturer so the case rips apart when it has been sized too many times? If that happens, it's going to be a pain to get it out of the sizing die...
Material savings?
Hmm, seems totally unnecessary on the case. Would it prevent certain bullets from being used, like 300 gr.?It is a cannelure. A groove rolled into the case body to stop bullet set back and for identification.https://en.wikipedia.org/wiki/Cannelure
Hmm, seems totally unnecessary on the case. Would it prevent certain bullets from being used, like 300 gr.?
Hmm, seems totally unnecessary on the case…
Is it for the bullets that don't have a crimp cannelure, or just an extra measure of safety?Only to those ignorant of its function. The cannelure prevents the bullet from being driven deeper into the case, as in a tubular magazine. The first firing usually irons it out and all that is left is a shadow on the case. I’ve loaded thousands of .45 LC cartridges with those cannelures and have never seen a problem related to them. Don’t overthink this, just load and shoot.
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Is it for the bullets that don't have a crimp cannelure, . .
. . . or just an extra measure of safety?
In the era of lever carbines in calibers like .45 Colt, it was extra assurance that the bullet wouldn't be pushed down in the case farther, which would have caused dangerous over pressure. Modern levers don't need it, nor do revolvers really. Load 'em up and Choot 'em!
Automobiles.What features do "modern levers" have that "older/antique levers" do not that makes them unnecessary?
In the era of lever carbines in calibers like .45 Colt, it was extra assurance that the bullet wouldn't be pushed down in the case farther, which would have caused dangerous over pressure. Modern levers don't need it, nor do revolvers really. Load 'em up and Choot 'em!
Automobiles.
Not nearly as many folks galloping hither and yon, yon and hither, across the fruited plains, with lever carbines bouncing around next to a horse’s withers in a scabbard.
Gravity, bouncing and vibration play heck with loose cartridge necks.
I'm pretty sure 45 colt didn't apoear in levers until the 1970's
In the Colt cartridge, it’s probably got more to do with packaging than use. The packaging for cartridges used to be stiff paper wrapped and folded around a stack of loaded cartridges. Put them in a pile and the bottom “box” is bound to get a little squished. With black powder cartridges that’s not such a big deal but with smokeless, that can be a problem. That cannelure won’t hold up against a lot of weight but it will bulge if the base is pushed past it. Gives a visual and tactile warning that something’s not quite right.
I've seen the perforation more on 38 SPL than anything else. The comments about preventing setback make sense to me...38 SPL was THE short barrel revolver round back in the day, and some of those snubbies had some serious recoil...I would think the rise of snubby revolvers probably increased the possibility and occurences of setback, so the mid case crimp makes sense to me there.