Lets discuss cannelure

DaveTN

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I've seen varying thoughts on whether to crimp on a cannelure or not. I'd like to hear what you guys here have to say about it. I haven't loaded any rifle ammo yet and I need a plan. I'm not a reloading expert, I'm a retired Toolmaker, and therefore not crimping on a cannelure seems like a bad idea to me for ammo that might be banged around in transport or used in a magazine. The possibility of a bullet moving seems like a bad idea.

I'm be loading .223 and .308 for range use, no hunting. I'm not using high dollar match bullets, just mostly experimenting with different weight FMJ. .223 will be used in an AR. The .308 I'm going to try to see if I can load something that will work well in both my .308 bolt and .308 AR10.

I loaded some handgun ammo and had good luck with that. Time to do some rifle ammo.

I see comments about accuracy suffering with a crimp on a cannelure. How much are we talking, generally speaking?

And if you aren't crimped on a on a cannelure how do you know you have enough crimp to keep the bullet from moving?
 

Lost Lake

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I'm not a benchrest shooter, so I'm not interested in gnat-sized bughole groups. It'd be fine if it happens though, but I'm not going to obsess over it.
There are arguments over crimping or not affecting accuracy.
Most times the cannelure is in the proper place for COAL, but I might seat bullets out farther, and I'll ignore the cannelure, most bullets that I use don't have one.

With hunting ammo in my bolt actions, I still put a light crimp on my ammo in case of bullet setback in the magazine during recoil. Even though simple neck tension should be enough, I still do it. I don't want any surprises in the field.

With my tube fed lever actions, especially my big bore levers, I use a Lee Factory Crimp die and go on the heavy side. I've seen factory ammo suffer from considerable bullet setback from simple magazine spring tension from loading, never mind the recoil.
 

Omega

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I never had any issues with just paying attention to COAL and the jump. I do however have a tool to put cannelure on a bullet if I find I need one. I wanted to have a setup to swage bullets, which would give me bullets without one.
 

Omega

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What would cause you to need one?
I planned on swaging bullets for my AR, which, supposedly, move more than say my bolt actions. I have not had that issue, but the tool was a good deal and if for some reason I find a load that seems to open up for no other reason I can add one.
 

Remi

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I crimp revolvers and tube fed


I've had an ar10 and didn't crimp for it. They won't "bang a round" any more than a bolt gun. I shoot with several guys that shoot an ar10 and none of them crimp either


If you want to crimp use the Lee FCD. It won't matter if you have a cannalure or not.


A friend was dead set on crimping for his ar15 because he was afraid of setback. We loaded a 60gr vmax with no crimp and ran it through the mag into the chamber, eject to the floor, reload and repeat 20 times with the same round. There was no change in length and no change in concentricity.
 
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