The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > Handloading, Reloading, and Bullet Casting

Reply
 
Thread Tools Search this Thread
Old January 4, 2006, 11:45 AM   #1
tegemu
Senior Member
 
Join Date: October 14, 2005
Location: Orange Park, Fla
Posts: 1,019
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.
__________________
People sleep peaceably in their beds at night only because rough men stand ready to do violence in their behalf. - George Orwell
tegemu is offline  
Old January 4, 2006, 12:39 PM   #2
Thirties
Senior Member
 
Join Date: April 29, 2001
Location: Where the Red Sox meet the Black Bears
Posts: 561
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.



.
Thirties is offline  
Old January 4, 2006, 01:24 PM   #3
kingudaroad
Senior Member
 
Join Date: March 11, 2005
Location: austin
Posts: 735
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.
kingudaroad is offline  
Old January 4, 2006, 01:35 PM   #4
tegemu
Senior Member
 
Join Date: October 14, 2005
Location: Orange Park, Fla
Posts: 1,019
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?
__________________
People sleep peaceably in their beds at night only because rough men stand ready to do violence in their behalf. - George Orwell
tegemu is offline  
Old January 4, 2006, 02:19 PM   #5
Leftoverdj
Senior Member
 
Join Date: October 15, 2004
Posts: 934
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.
Leftoverdj is offline  
Old January 4, 2006, 02:28 PM   #6
Thirties
Senior Member
 
Join Date: April 29, 2001
Location: Where the Red Sox meet the Black Bears
Posts: 561
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
Thirties is offline  
Old January 4, 2006, 08:42 PM   #7
BigJakeJ1s
Senior Member
 
Join Date: August 8, 2005
Location: Arlington TX
Posts: 663
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
BigJakeJ1s is offline  
Old January 22, 2006, 07:24 AM   #8
skeet47
Member
 
Join Date: November 2, 2005
Posts: 50
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.
skeet47 is offline  
Old January 22, 2006, 07:53 AM   #9
caz223
Senior Member
 
Join Date: May 15, 2002
Location: Michigan
Posts: 1,429
+1 on the light factory crimp in .45....
__________________
I'm not just a gun.
I'm YOUR gun.
(Hold me.)
caz223 is offline  
Old January 22, 2006, 02:30 PM   #10
Bullet94
Senior Member
 
Join Date: September 8, 2004
Location: Kansas
Posts: 723
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.
__________________
PRO-SECOND AMENDMENT - Live Free or Die
Bullet94 is offline  
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 11:01 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.07798 seconds with 10 queries