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Crimping Question

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28 May 2007, 20:53
Leo M
Crimping Question
On bullets with a cannelure, where should the bullet be seated with respect to the case mouth? Bottom edge, middle or the top edge of the cannelure. Thanks for any help.
28 May 2007, 21:24
Woodrow S
I crimp my reloads with about 1/4 of the cannelure showing. That way I know the case mouth is fully crimped into the cannelure.
28 May 2007, 22:34
onefunzr2
I guess it depends what movement you're trying to prevent...bullet going deeper into the case like a tubular magazine lever gun, or keeping it from growing longer and stopping the revolver cylinder from turning.

You had best trim your cases to equal length if you chose top or bottom of the cannelure.
28 May 2007, 23:15
Leo M
This would be for a .375 H & H magnum.
29 May 2007, 06:34
Woodrow S
Leo,

I thought you were referring to a handgun or lever gun too. I don't crimp my rifle reloads at all, not even my 375 H&H and I never had an issue. Now if you are talking the big kickers then I can see doing it(and even then inspect your ammo if it was in the magazine while firing the one in the chamber ). Take a look at some factory loaded 375 H&H ammo. They are always crimped. That should give you a good reference point.

Woody
31 May 2007, 08:46
BlackHawk1
I seat Hornady Interlocks, which have cannelures, to where the top of the cannelure is barely visible above the case mouth and give a medium crimp with a Lee Factory Crimp Die. The cases are equally trimmed to ensure consistency.


BH1

There are no flies on 6.5s!
31 May 2007, 20:17
Gustavo
For hunting purposes I will ALWAYS apply a crimp.

I demand perfect mechanical functioning, especially when cycling, extracting and ejecting.

I've had bad experiences with not so crimped heavy recoiling ammo...not again and not in the middle of the field Frowner


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01 June 2007, 16:03
Gerry
Leo,

Looks like you've received several differing opinions on this topic.

FWIW, I use a Lee Case Length Trimmer (length consistancy) & a Lee Factory Crimp Die on my .375H&H loads with a 300 grain PMP Round Nose Soft Point. The bullet has a crimping groove and like Woodrow & Blackhawk stated; I seat the bullets with just a tad bit of cannelure above the mouth of the case. Like they do; I figure I'm using about as much of the canelure for the crimp as I can.

Anyway, seems to work and the loads are accurate, too.


Cheers,

Number 10
01 June 2007, 18:34
Rikkie
Just to throw the cat among the pigeons - one of the final steps in my load development (for accuracy) is to tweak OAL. Some of my loads are thus crimped with the entire cannelure showing above the case neck. When using the Lee Factory Crimp die, this is not an issue. To answer your question more directly, I don't let the cannelure (any part of it) determine OAL for me, unless by pure coincidence.
01 June 2007, 19:39
Wink
Different types of bullets have different types of cannelures. For those that have a V-shaped groove I use the normal seater dies' roll crimp (as a second step after bullet seating) and seat so that the case lip most precisely seats into the V-cannelure. For bullets that have a recessed band I use the Lee Factory crimp and seat the bullet to the top of the cannelure band, allowing the Factory Crimp to compress the case lip so that there is practically nothing to catch during feeding.


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