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Old January 4, 2006, 11:45 AM   #1
tegemu
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Advice Please?

To achieve the smoothest, most positive feeding of my reloaded rounds, which would be best, Taper Crimp or Factory Crimp? Or is there another crimp that this neophyte is unaware of? Thank You.
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Old January 4, 2006, 12:39 PM   #2
Thirties
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If you are planning to load ammo, you had better buy and read a few loading manuals. Several of the reloading manuals give good explanations with pictures and diagrams. I recommend Speer #13 as a good start...


Taper crimp is what it sounds like. The die creates a slightly tapered profile removing the belling made by the expander die. These are important for semi-auto pistol feeding. You don't want edges on the ammo.

The other type of crimp is the roll crimp which are used in bullets with crimping groves, or used with wadcutter bullets over the front. Roll crimp, sometimes called profile crimp is usually used in revolvers.

Factory Crimp is a trademark name of the Lee company. Go to their website to read about them. They crimp the case and they resize the case as well, giving the round a squeeze.



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Old January 4, 2006, 01:24 PM   #3
kingudaroad
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Please tell us what cartridge you are loading. If you have "feeding" concerns it sounds like you may be loading for a semi-auto pistol in which case there is no crimp required, but merely unbelling the case mouth back to its original diameter.
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Old January 4, 2006, 01:35 PM   #4
tegemu
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Thanks guys. I have, and am, reading "The ABC's of Reloading" but was still unclear as to this question. From what you have told me, it is the taper crimp that I had in mind. I have been away from shooting and reloading for a loooong time and am getting reacquanted and plan to reload 45ACP. Smooth transition from Magazine to Chamber is what I am concerned about. At the moment I am gathering my wits about me to decide what eguipment to acquire, dies etc., hence I wanted to get the correct die and had been advised variously that I wanted either a Taper, or a Roll, or a Factory Crimp. As I understand it, the Taper Crimp would be the 4th Die, correct?
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Old January 4, 2006, 02:19 PM   #5
Leftoverdj
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You don't wanna crimp the .45 ACP. It headspaces on the case mouth so you just want to take the flare out, and the seating die works fine for that.
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Old January 4, 2006, 02:28 PM   #6
Thirties
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Taper crimp die can be in the 4th position, but you will be able to use the seating die to seat and taper crimp in one action, if you wish.

ABCs of Loading is not at all the best book on the subject. Seriously, you should already have at least a couple of loading manuals before you choose equipment.

Two good ones that should be in your library:

Speer #13
Lyman #48
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Old January 4, 2006, 08:42 PM   #7
BigJakeJ1s
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Different cartidges have different methods of ensuring that the cartridge feeds into the chamber to exactly the correct depth (to make sure the primer is right where it needs to be for the firing pin to hit it). This method is called headspacing.

Some cartridges headspace when the rim hits the back of the chamber (a lot of revolver cases, and older, rimmed rifle cases like 30-30, etc.). Most bottleneck cartridges (not all!) headspace when the shoulder of the cartridge contacts the the corresponding shoulder in the chamber. Belted magnum rifle cartridges headspace when the belt hits the corresponding ridge in the chamber. Finally, most straight wall, rimless pistol cartridges (9mm, 45 acp, etc.) headspace when the top of the brass hits a ridge at the front of the chamber (called headspacing on the case mouth).

Different means of crimping are needed based on whether a cartridge headpsaces on the case mouth or not. Since a roll crimp distorts the casemouth, it should not be used when the cartridge headspaces on the case mouth, but the taper crimp should be used instead. The idea behind the taper crimp is to just take the flare out of the case mouth (that was flared to make seating the bullet easier), leaving the end of the brass to headspace in the chamber. Taper crimping can also be used on other cartridges with bullets that don't have a crimping groove, called a cannelure. Roll crimping, with the right cartridge and bullet, is generally easier to do (more forgiving), and secures the bullet better.

Hope this helps,

Andy
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Old January 22, 2006, 07:24 AM   #8
skeet47
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Crimp

As a commercial loader I found out long ago that the Lee Factory crimp die properly used will insure 100% feding of your ammo in anything.
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Old January 22, 2006, 07:53 AM   #9
caz223
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+1 on the light factory crimp in .45....
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Old January 22, 2006, 02:30 PM   #10
Bullet94
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This question gets asked a lot so I copied this from one of my reloading manuals –

Taper crimping should remove any flare left on the case mouth from the neck expanding step and squeeze in the case mouth tightly against the bullet. After the flare is removed from the case mouth the case should not be reduced in diameter by more than .001” or .002”. Any more than this, and the bullet will be deformed in this area. Of course accuracy will then be effected. Cast bullets, especially when made from a soft alloy, are particularly vulnerable.
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