Roll Crimp vs Taper Crimp

Freedom528 · February 13, 2008, 10:27 AM

Starting this month, I plan to re-load for a .357 magnum revolver, but in the near future, I would also like to add a .357 magnum lever-action rifle to my collection and reload for that as well.

Which style of reloading dies would be better: one with a taper crimp or one with a roll crimp? Typically, I buy carbide dies for handgun cartridges and the bullets will be 158 grain jacketed hollow points.

Any advice will be appreciated.

UGH · February 13, 2008, 10:37 AM

I would and do use a Lee factory crimp die for 357. In fact I use them for all pistol calibers.

Sevens · February 13, 2008, 10:55 AM

You'll find that most bullet seating dies also come equipped to apply either a roll or taper crimp according to caliber. My .357 mag seating die will put on a nice firm roll crimp if I have the die adjusted in to do so. My .45 auto seating die will give the case a modified taper crimp while not rolling up the edge of the brass which could compromise seating in the chamber.

The biggest reason for a solid roll crimp in a revolver caliber is to keep bullets in other rounds in the cylinder from creeping forward under heavy recoil. Another reason to crimp is to allow pressure to build for a stout magnum hot round. In the case of a lever action rifle, a decent crimp is also piece of mind considering the cartridges are in a spring-loaded tube magazine.

The biggest reason for a good taper crimp in a semi-auto pistol round is to insure there is no chance of bullet setback when the pistol racks a fresh round in to the chamber. If there's little or no mouth tension on the bullet, a projectile could be push back in to the case and raise pressures exponentially. This is a very unsafe condition.

zxcvbob · February 13, 2008, 11:04 AM

Your .357 die set (make sure you get one that can also do .38 Specials, if in doubt buy a .38 Special die set because they always can do .357's) will be able to do a roll crimp, which is what's normally done for all revolver cartridges. You can also try using your 9mm seating die to do a taper crimp and see which works better. The taper crimp might actually be better if the bullets do not have a cannelure.

Revolver bullets tend to jump forward and jam the gun if not crimped enough. And in a tubular magazine rifle, the bullets can press into the case (like an autoloading pistol) if they are not crimped enough.

TexasSeaRay · February 13, 2008, 11:45 AM

As usual, Sevens and zxcvbob nail it, these two should get together and author a "Handloading For The Beginner" series and publish it. . . so I'll only add that my "rule" is pretty simple for a simple-minded reloader such as myself.

For handgun calibers, if it's a straight-wall handgun case, I apply a roll crimp. If it's a tapered case/semi-auto caliber case, I apply a taper crimp--even if I'm going to be shooting it out of a revolver. That's worked pretty well for me over the years.

I don't load much long gun or rifle ammo, although I'm about to get a lot more into that, but I always roll crimp my flat-nose 30-30 since it's going in the tube magazine of my Model 94.

Jeff

Bullet94 · February 13, 2008, 10:28 PM

Freedom528
Roll crimp your 357 cartridges.

Taper crimping is only supposed to remove the flare from belling. Nothing to do with Bullet setback. Bullet setback is prevented by proper case tension.

Freedom528 · February 14, 2008, 07:59 AM

Thanks for the information. Lots of good advise in this forum.

Alleykat · February 15, 2008, 06:52 PM

Quote:

Taper crimping is only supposed to remove the flare from belling. Nothing to do with Bullet setback. Bullet setback is prevented by proper case tension.

That's EXACTLY right; futhermore, you should never roll crimp, unless you're roll crimping into a cannelure.

Eazmo · April 21, 2011, 11:45 PM

yes i dug this one up from the past.

I have some 125gr Rainer bullets that i want to load in 38 special.
On there site they recommend a taper crimp. http://www.rainierballistics.com/faq.htm
I understand that as these have no cannelure groove .

So my question is about loading these with a Lee Carbide 4 die set.
I understand the seating die will apply a crimp. IS it a taper crimp?

I also understand the factory crimp die for revolvers is a roll crimp. do i not want to use this die for final crimp with these Rainer's that have no cannelure?

Thanks for any input

BigBob3006 · April 22, 2011, 12:15 AM

Freedom,

I've worked on three pistol loads to be shot in rifles. These were The .357 Mag, .44 Mag and the .45 Long colt. The load for the pistol side of pairing was selected as the control side. After working up a good load in the pistols the same load shot in the Marlin rifles. All shot great and were a lot of fun to shoot.

As for crimping, The taper crimp is intended for use on semi-automatics such as the Colt .45 ACP. The roll crimp is used for revolver and rifle cartridges.
So look up the pistol load in your manual and it will work fine in your rifle.

Eagle0711 · April 22, 2011, 12:54 AM

Either will work. I've always roll crimped, but bought a TC die and it works great

For heavy loads you want a heavy roll crimp that will allow better burning of the powder. I always keep the cyl. open on my gun and slip each one in after seating and crimping to make sure that they all chamber when shooting. If lightly crimping the bell may not be removed enough to chamber freely.

Having a failure in a match is embrassing and poeple will think that you don't know what you're doing. especially when using speed loaders.

FlyFish · April 22, 2011, 07:04 AM

The choice between roll or taper crimping is dictated by the cartridge, specifically how it headspaces. Most semi-auto handgun cartridges headspace on the case mouth and must be taper-crimped so that an edge remains to bear on the step in the chamber and provide proper headspacing. Revolver cartridges typically headspace on the rim, so are usually roll-crimped, but can be taper-crimped if you wish and, in the case of bullets without a cannelure, should be taper-crimped. Roll-crimping a cartridge that headspaces on the case mouth may allow it to move too far forward in the chamber, potentially leading to ignition and other problems.

Sevens · April 22, 2011, 07:54 AM

I'm not familiar enough with the Lee Carbide Factory Crimp die to know if it roll crimps or not. I can tell you that a Lee rifle factory crimp die is neither a roll nor taper crimp -- it squeezes the case in mid-neck and applies a different kind of crimp entirely.

Ranier may suggest that you taper crimp your .38 Special loads but if you do, you'll be one of very few people on earth that does that.

When using a plated bullet, all you need to keep in mind is that you don't want a heavy roll crimp because a heavy crimp can cut through the razor thin plating. And in my experience, Ranier plated bullets have some of the thinnest plating out there in all of plated bullets.

Loading a light or medium .38 Special load, you don't really need a crimp. You need to remove the belling from the mouth flare step, but that's about it.

A heavy crimp in a revolver isn't necessary unless it's a heavy-recoil round or if it's a slow-burning powder magnum load that needs the heavy resistance of a roll crimp to allow a full burn. In .38 Special, you don't likely need either.

With the bullets you have and the dies you have, my suggestion would be to skip the factory crimp die, simply use the 3 dies you have and put a very, very, very light roll crimp on your rounds.

Best way to check? Set your crimp, make sure the rounds will chamber easily, then use a bullet puller to pull down one of the rounds and make sure the crimp isn't severe in the bullet and make sure it's not cutting the plating.

Eazmo · April 22, 2011, 07:56 AM

Quote:

Revolver cartridges typically headspace on the rim, so are usually roll-crimped, but can be taper-crimped if you wish and, in the case of bullets without a cannelure, should be taper-crimped.

So can i accomplish a taper crimp with a Lee carbide 4 die 38spl/.357 set or do i need to purchase a taper crimp die?

Thanks

FlyFish · April 22, 2011, 08:37 AM

Because you're dealing with a cartridge that headspaces on the rim, whether it's a true taper crimp or not doesn't really matter. You should be able to adjust the die to lightly return the case neck to approximate a taper crimp or a light roll crimp - all you're really trying to do is get the case mouth back to where the cartridge will chamber easily without deforming the bullet.

wncchester · April 22, 2011, 08:46 AM

I don't think you have a problem. Cartridges are generally made and intended for use in revolvers or autos. Autos generally use taper crimps and revolvers use roll crimps and none of that's a secret to out die makers; all dies I've seen in more than four decades of reloading are correct for the type. I doubt anyone has even made a taper crimper for revolver loads, there would be no point to it.

Eazmo · April 22, 2011, 08:57 AM

Quote:

I doubt anyone has even made a taper crimper for revolver loads, there would be no point to it.

Yes, Lee makes one that's one of the reasons i was asking.
I'm gunna just play with the amount of crimping on some dummy rounds and see how things look.
Thanks

totaldla · April 22, 2011, 10:30 AM

A proper roll crimp requires brass at all the same length. The Lee FCD does not.

Eagle0711 · April 22, 2011, 12:49 PM

RCBS makes a Taper Crimp die. I like it better for two reasons. You don't have to trim all of that brass to get a consistant crimp, and the brass will last longer because of the splits from working the brass at the crimping area.

Eazmo · April 22, 2011, 10:10 PM

Quote:

RCBS makes a Taper Crimp die. I like it better for two reasons. You don't have to trim all of that brass to get a consistant crimp, and the brass will last longer because of the splits from working the brass at the crimping area.

Thanks i'll check it out

Clifford L. Hughes · April 23, 2011, 07:17 PM

Freedom528:

The resopnses the you received are accurate. However, I use a slightly different method. I seat the bullets to the proped depth without crimping and then I come back and I crimp. I load a lot of .45 ACP, 210 gr. lead semi waddcutters. Because the case head spaces on the case mouth I taper crimp. My 3.5 grs. Bullseye load is light recoiling and the bullets don't jump in the cases and I experience no malfunctoins. Using a roll crimp I have had miss fires.

However, for my Smith & Wesson 625 I shoot heavy loads that require a heavy crimp. For the revolvers I don't have a head space issue.

Semper Fi.

Gunnery sergeant
Clifford L. Hughes
USMC Retired

Nevmavrick · April 24, 2011, 08:48 AM

My guess is that most of the members are too young to remember the die sets that were made when I started reloading. There were 4 dies.
Clifford L. has the right idea. I do the same.
Since most of my handgun reloading is done with lead, which is larger, I seat the bullet, then crimp it. My .45 ACP is seated with a .45 Colt die, then crimped with an ACP die.
When I load my .41Mag, I run the die just barely into the press, and run the seating stem down 'til it will seat the bullet at the needed depth. Then I, as a 4th step, run the die in 'til I can crimp it the required amount.
Have fun,
Gene

Walkalong · April 25, 2011, 09:58 PM

For jacketed bullets with a cannelure, the norm is to roll crimp, and that is what the die set for that caliber will have. That is what I recommend.

You can also taper crimp revolver rounds when using jacketed bullets with a cannelure, and you can use a heavy taper crimp, but will have to crimp in a second step. Works just fine.

With the roll crimp into a good cannelure you can seat and crimp in the same step, or in a separate step, whichever you prefer.

Quote:

A proper roll crimp requires brass at all the same length. The Lee FCD does not.

The FCD for rifle does not, but the FCD for pistol crimps like any other crimper, and consistent case length will help it just like any other crimp die. I trim all of my revolver brass, although some people don't, even when roll crimping.

WESHOOT2 · April 27, 2011, 05:34 AM

Finish with the Redding Profile Crimp die; it offers both based on adjustment.

Ivan · April 27, 2011, 06:21 AM

I do pretty much what Clifford L. Hughes and Nevmavrick do but with an extra taper crimp die in a progressive press.

The reason is because if you seat and crimp in one step, the bullet is still being pushed deeper as the case is being crimped. At some point, the bullet is already touching the bullet's side and seating the bullet deeper will shave lead or copper plating (jackets are tougher). Sometimes a crimping groove matches up so that the case is crimped into that groove, but sometimes it doesn't. This method seems to work pretty consistently so I use it.

- Ivan.

February 13, 2008, 10:27 AM	#1
Freedom528 Junior Member Join Date: July 30, 2007 Posts: 5	Roll Crimp vs Taper Crimp Starting this month, I plan to re-load for a .357 magnum revolver, but in the near future, I would also like to add a .357 magnum lever-action rifle to my collection and reload for that as well. Which style of reloading dies would be better: one with a taper crimp or one with a roll crimp? Typically, I buy carbide dies for handgun cartridges and the bullets will be 158 grain jacketed hollow points. Any advice will be appreciated.

February 13, 2008, 10:37 AM	#2
UGH Senior Member Join Date: October 3, 2007 Posts: 156	I would and do use a Lee factory crimp die for 357. In fact I use them for all pistol calibers. __________________ If you liberals keep gettin' your way - we're all gonna hear one big loud flush. The sound of the U.S. of A. goin' straight down the toilet.- Archie Bunker............. Firearms are second only to the Constitution in importance; they are the peoples' liberty's teeth. George Washington

February 13, 2008, 10:55 AM	#3
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	You'll find that most bullet seating dies also come equipped to apply either a roll or taper crimp according to caliber. My .357 mag seating die will put on a nice firm roll crimp if I have the die adjusted in to do so. My .45 auto seating die will give the case a modified taper crimp while not rolling up the edge of the brass which could compromise seating in the chamber. The biggest reason for a solid roll crimp in a revolver caliber is to keep bullets in other rounds in the cylinder from creeping forward under heavy recoil. Another reason to crimp is to allow pressure to build for a stout magnum hot round. In the case of a lever action rifle, a decent crimp is also piece of mind considering the cartridges are in a spring-loaded tube magazine. The biggest reason for a good taper crimp in a semi-auto pistol round is to insure there is no chance of bullet setback when the pistol racks a fresh round in to the chamber. If there's little or no mouth tension on the bullet, a projectile could be push back in to the case and raise pressures exponentially. This is a very unsafe condition. __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.

February 13, 2008, 11:45 AM	#5
TexasSeaRay Senior Member Join Date: November 19, 2007 Location: Texas Posts: 810	As usual, Sevens and zxcvbob nail it, these two should get together and author a "Handloading For The Beginner" series and publish it. . . so I'll only add that my "rule" is pretty simple for a simple-minded reloader such as myself. For handgun calibers, if it's a straight-wall handgun case, I apply a roll crimp. If it's a tapered case/semi-auto caliber case, I apply a taper crimp--even if I'm going to be shooting it out of a revolver. That's worked pretty well for me over the years. I don't load much long gun or rifle ammo, although I'm about to get a lot more into that, but I always roll crimp my flat-nose 30-30 since it's going in the tube magazine of my Model 94. Jeff __________________ If every single gun owner belonged to the NRA as well as their respective state rifle/gun association, we wouldn't be in the mess we're in today. So to those of you who are members of neither, thanks for nothing.

February 13, 2008, 10:28 PM	#6
Bullet94 Senior Member Join Date: September 8, 2004 Location: Kansas Posts: 723	Freedom528 Roll crimp your 357 cartridges. Taper crimping is only supposed to remove the flare from belling. Nothing to do with Bullet setback. Bullet setback is prevented by proper case tension. __________________ PRO-SECOND AMENDMENT - Live Free or Die

February 13, 2008, 11:04 AM	#4
zxcvbob Senior Member Join Date: December 20, 2007 Location: S.E. Minnesota Posts: 4,720	Your .357 die set (make sure you get one that can also do .38 Specials, if in doubt buy a .38 Special die set because they always can do .357's) will be able to do a roll crimp, which is what's normally done for all revolver cartridges. You can also try using your 9mm seating die to do a taper crimp and see which works better. The taper crimp might actually be better if the bullets do not have a cannelure. Revolver bullets tend to jump forward and jam the gun if not crimped enough. And in a tubular magazine rifle, the bullets can press into the case (like an autoloading pistol) if they are not crimped enough.

February 14, 2008, 07:59 AM	#7
Freedom528 Junior Member Join Date: July 30, 2007 Posts: 5	Thanks for the information. Lots of good advise in this forum.

April 21, 2011, 11:45 PM	#9
Eazmo Senior Member Join Date: April 15, 2011 Location: Arizona Posts: 164	yes i dug this one up from the past. I have some 125gr Rainer bullets that i want to load in 38 special. On there site they recommend a taper crimp. http://www.rainierballistics.com/faq.htm I understand that as these have no cannelure groove . So my question is about loading these with a Lee Carbide 4 die set. I understand the seating die will apply a crimp. IS it a taper crimp? I also understand the factory crimp die for revolvers is a roll crimp. do i not want to use this die for final crimp with these Rainer's that have no cannelure? Thanks for any input

April 22, 2011, 12:15 AM	#10
BigBob3006 Member Join Date: February 19, 2011 Location: Rio Rancho, New Mexico Posts: 80	Freedom, I've worked on three pistol loads to be shot in rifles. These were The .357 Mag, .44 Mag and the .45 Long colt. The load for the pistol side of pairing was selected as the control side. After working up a good load in the pistols the same load shot in the Marlin rifles. All shot great and were a lot of fun to shoot. As for crimping, The taper crimp is intended for use on semi-automatics such as the Colt .45 ACP. The roll crimp is used for revolver and rifle cartridges. So look up the pistol load in your manual and it will work fine in your rifle. __________________ Have a nice day. Good luck and God bless. Bob Last edited by BigBob3006; April 22, 2011 at 12:23 AM. Reason: I boo-booed

April 22, 2011, 12:54 AM	#11
Eagle0711 Senior Member Join Date: August 25, 2010 Posts: 782	Either will work. I've always roll crimped, but bought a TC die and it works great For heavy loads you want a heavy roll crimp that will allow better burning of the powder. I always keep the cyl. open on my gun and slip each one in after seating and crimping to make sure that they all chamber when shooting. If lightly crimping the bell may not be removed enough to chamber freely. Having a failure in a match is embrassing and poeple will think that you don't know what you're doing. especially when using speed loaders.

April 22, 2011, 07:04 AM	#12
FlyFish Senior Member Join Date: January 20, 2009 Location: Overlooking the Baker River Valley Posts: 1,723	The choice between roll or taper crimping is dictated by the cartridge, specifically how it headspaces. Most semi-auto handgun cartridges headspace on the case mouth and must be taper-crimped so that an edge remains to bear on the step in the chamber and provide proper headspacing. Revolver cartridges typically headspace on the rim, so are usually roll-crimped, but can be taper-crimped if you wish and, in the case of bullets without a cannelure, should be taper-crimped. Roll-crimping a cartridge that headspaces on the case mouth may allow it to move too far forward in the chamber, potentially leading to ignition and other problems.

April 22, 2011, 07:54 AM	#13
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	I'm not familiar enough with the Lee Carbide Factory Crimp die to know if it roll crimps or not. I can tell you that a Lee rifle factory crimp die is neither a roll nor taper crimp -- it squeezes the case in mid-neck and applies a different kind of crimp entirely. Ranier may suggest that you taper crimp your .38 Special loads but if you do, you'll be one of very few people on earth that does that. When using a plated bullet, all you need to keep in mind is that you don't want a heavy roll crimp because a heavy crimp can cut through the razor thin plating. And in my experience, Ranier plated bullets have some of the thinnest plating out there in all of plated bullets. Loading a light or medium .38 Special load, you don't really need a crimp. You need to remove the belling from the mouth flare step, but that's about it. A heavy crimp in a revolver isn't necessary unless it's a heavy-recoil round or if it's a slow-burning powder magnum load that needs the heavy resistance of a roll crimp to allow a full burn. In .38 Special, you don't likely need either. With the bullets you have and the dies you have, my suggestion would be to skip the factory crimp die, simply use the 3 dies you have and put a very, very, very light roll crimp on your rounds. Best way to check? Set your crimp, make sure the rounds will chamber easily, then use a bullet puller to pull down one of the rounds and make sure the crimp isn't severe in the bullet and make sure it's not cutting the plating. __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.

April 22, 2011, 08:37 AM	#15
FlyFish Senior Member Join Date: January 20, 2009 Location: Overlooking the Baker River Valley Posts: 1,723	Because you're dealing with a cartridge that headspaces on the rim, whether it's a true taper crimp or not doesn't really matter. You should be able to adjust the die to lightly return the case neck to approximate a taper crimp or a light roll crimp - all you're really trying to do is get the case mouth back to where the cartridge will chamber easily without deforming the bullet.

April 22, 2011, 08:46 AM	#16
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	I don't think you have a problem. Cartridges are generally made and intended for use in revolvers or autos. Autos generally use taper crimps and revolvers use roll crimps and none of that's a secret to out die makers; all dies I've seen in more than four decades of reloading are correct for the type. I doubt anyone has even made a taper crimper for revolver loads, there would be no point to it.

April 22, 2011, 10:30 AM	#18
totaldla Senior Member Join Date: August 10, 2009 Location: SW Idaho Posts: 1,295	A proper roll crimp requires brass at all the same length. The Lee FCD does not. __________________ Lee Auto Bench Prime Castor Oil Case Lube

April 22, 2011, 12:49 PM	#19
Eagle0711 Senior Member Join Date: August 25, 2010 Posts: 782	RCBS makes a Taper Crimp die. I like it better for two reasons. You don't have to trim all of that brass to get a consistant crimp, and the brass will last longer because of the splits from working the brass at the crimping area.

April 23, 2011, 07:17 PM	#21
Clifford L. Hughes Senior Member Join Date: February 24, 2011 Location: Southern Californis Posts: 795	Clifford L. Hughes Freedom528: The resopnses the you received are accurate. However, I use a slightly different method. I seat the bullets to the proped depth without crimping and then I come back and I crimp. I load a lot of .45 ACP, 210 gr. lead semi waddcutters. Because the case head spaces on the case mouth I taper crimp. My 3.5 grs. Bullseye load is light recoiling and the bullets don't jump in the cases and I experience no malfunctoins. Using a roll crimp I have had miss fires. However, for my Smith & Wesson 625 I shoot heavy loads that require a heavy crimp. For the revolvers I don't have a head space issue. Semper Fi. Gunnery sergeant Clifford L. Hughes USMC Retired

April 24, 2011, 08:48 AM	#22
Nevmavrick Senior Member Join Date: January 2, 2010 Location: Sparks, Nevada, near Reno Posts: 183	My guess is that most of the members are too young to remember the die sets that were made when I started reloading. There were 4 dies. Clifford L. has the right idea. I do the same. Since most of my handgun reloading is done with lead, which is larger, I seat the bullet, then crimp it. My .45 ACP is seated with a .45 Colt die, then crimped with an ACP die. When I load my .41Mag, I run the die just barely into the press, and run the seating stem down 'til it will seat the bullet at the needed depth. Then I, as a 4th step, run the die in 'til I can crimp it the required amount. Have fun, Gene

April 27, 2011, 05:34 AM	#24
WESHOOT2 Senior Member Join Date: February 20, 1999 Location: home on the range; Vermont (Caspian country) Posts: 14,324	Finish with the Redding Profile Crimp die; it offers both based on adjustment. __________________ . "all my ammo is mostly retired factory ammo"

April 27, 2011, 06:21 AM	#25
Ivan Senior Member Join Date: October 14, 2009 Posts: 141	I do pretty much what Clifford L. Hughes and Nevmavrick do but with an extra taper crimp die in a progressive press. The reason is because if you seat and crimp in one step, the bullet is still being pushed deeper as the case is being crimped. At some point, the bullet is already touching the bullet's side and seating the bullet deeper will shave lead or copper plating (jackets are tougher). Sometimes a crimping groove matches up so that the case is crimped into that groove, but sometimes it doesn't. This method seems to work pretty consistently so I use it. - Ivan.