Crimping without a cannelure

SwampYankee · November 1, 2008, 08:40 PM

I've looked for information on crimping different calibers and a lot of people have their preferences but I have not found an answer for one very specific question:

Can non-cannelured bullets be taper crimped? I assume that they can but if so, should be done lightly? Is it only cannelured bullets that can be roll crimped?

Thanks

wncchester · November 1, 2008, 09:28 PM

"I assume that they can but if so, should be done lightly?"

You are correct. Even if you are a Yankee.

TFL4L · November 1, 2008, 11:16 PM

I don't know about other dies, but the Lee Factory Crimp die is safe to use even with non-cannelured bullets.

SwampYankee · November 2, 2008, 01:01 PM

I am using all RCBS equipment that I have scratched together. I have put a taper crimp on both .40 S&W and .38 bullets without cannelures but I was worried that 1) it might increase pressures excessively or 2) it might damage the bullets.

The RCBS dies will taper crimp non-cannelured bullets and I have not seen any of the aforementioned symptoms, but this particular question is not addressed in any of the reloading manuals I have.

**Unclenick** · November 2, 2008, 01:40 PM

In general, a taper crimp is good with ammunition for self-loaders, since their recoil tends to try to push the bullets deeper into their cases by banging the magazine against their noses. The wedge of the case mouth into the bullet from a taper crimp stops that. A taper crimp works the brass less than a roll crimp, which means your cases last longer.

Revolvers, however, tend to extract the bullets on recoil by recoiling the chambers against the cartridge case rims, while the bullets try to stay still in space by inertia. For that reason, a roll crimp is generally preferred for revolvers, despite the higher cost in brass wear.

The exception is light target loads of very fast powder. These typically produce too little recoil to back bullets out or to knock them in in the self-loaders. They can, therefore, be crimped by either method.

wncchester · November 2, 2008, 03:46 PM

In addition to the above, autoloader handguns headspace off the case mouths so they must have taper crimps. If we roll crimp them, or even do heavy taper crimps, it can easily allow the mouth to slid past the end of the chamber a small amount. If the case is too far forward it can cause misfires because of weak firing in impact. In theory, it could also cause pressues to climb significantly because the case mouth can't fully release the bullets.

Loader9 · November 2, 2008, 06:04 PM

There's also the option of putting a cannelure on the bullet where you want it. I have a tool by C-H very similar to this on FleaBay.

http://cgi.ebay.com/Cannelure-Tool-f...em370096288025

I put cannelures on bullet all the time. If I'm reloading some 38-40, I need a cannelure but no jacketed bullets available so I put a cannelure on a 40 SW 180gr XTP and call it good. You can do it with all types of bullets including ones that already have cannelures but not in the right spot for your particular gun. It's something to consider if you get into old cartridges or specialty cartridges.

SwampYankee · November 3, 2008, 11:09 PM

I know this is going to sound dumb, but how to you tell you dies are roll crimping or taper crimping? I have assumed that mine are taper crimping, but how would I know?

SwampYankee · November 5, 2008, 07:02 AM

Just a follow up, after some research I have discovered that apparently all RCBS dies are roll crimping, unless they are marked "TC" for taper crimp. I thought the TC was for tungsten carbide!

shu · November 6, 2008, 10:18 PM

Yes, the general rule seems to be: taper crimp for semi-automatic calibers, which cases have no rim and therefore headspace on the case mouth; roll crimp for revolver cartridges, which cases have a rim to control seating depth in the cylinder (and which, for my winchester 94 lever gun, might otherwise have the bullets pushed back into the cases while stacked in the feed tube).

Now for 357sig, which is supposed to headspace on the case mouth, I have intentially overcrimped (RCBS dies) an empty case and it puts a nice profound roll on the case mouth. Also I have shaved down an empty case with a case trimmer, and the case seems to headspace properly on the bottleneck.

So, since I am paranoid about bullet setback in 357sig, a couple of months ago I ordered one of those C&H canelure makers (the price on the ebay link above seems $20.00 or more to high). Just a few evenings ago, to keep calm and focused during evening of election day, I turned out the first set of test rounds with hornaday plated flat point bullets.

The canelure maker works fine. Soon as I get a chance I'll see if there is any difference in accuracy with and without canelure.

But to answer the question, I would say no problem to use taper crimp dies with a canelured bullet. However I would think roll crimp dies would only work properly with a canelured bullet; what ya gonna roll the lip into if there aint no groove in the bullet?

That's my story, and I'm sticking to it. - shu

TEDDY · November 7, 2008, 02:34 PM

I roll crimp all my pistol bullets.some have channels and some dont.what did shooters do before taper crimp???any one wonder.I dont heaspace on mouth of 45.as far as I am aware I head space on face of slide.slide drives case in to chamber and stops.the bullet is jammed into chamber.my loads will
keep in the X ring at 50 ft.and at 50 yds will do the same.now ball factory loads are different.

November 1, 2008, 08:40 PM	#1
SwampYankee Registration in progress Join Date: November 1, 2008 Location: I can be found on a number of other forums. Posts: 1,333	Crimping without a cannelure I've looked for information on crimping different calibers and a lot of people have their preferences but I have not found an answer for one very specific question: Can non-cannelured bullets be taper crimped? I assume that they can but if so, should be done lightly? Is it only cannelured bullets that can be roll crimped? Thanks

November 2, 2008, 01:40 PM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	In general, a taper crimp is good with ammunition for self-loaders, since their recoil tends to try to push the bullets deeper into their cases by banging the magazine against their noses. The wedge of the case mouth into the bullet from a taper crimp stops that. A taper crimp works the brass less than a roll crimp, which means your cases last longer. Revolvers, however, tend to extract the bullets on recoil by recoiling the chambers against the cartridge case rims, while the bullets try to stay still in space by inertia. For that reason, a roll crimp is generally preferred for revolvers, despite the higher cost in brass wear. The exception is light target loads of very fast powder. These typically produce too little recoil to back bullets out or to knock them in in the self-loaders. They can, therefore, be crimped by either method. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

November 6, 2008, 10:18 PM	#10
shu Senior Member Join Date: May 11, 2000 Location: lower rio grande valley, texas Posts: 216	Yes, the general rule seems to be: taper crimp for semi-automatic calibers, which cases have no rim and therefore headspace on the case mouth; roll crimp for revolver cartridges, which cases have a rim to control seating depth in the cylinder (and which, for my winchester 94 lever gun, might otherwise have the bullets pushed back into the cases while stacked in the feed tube). Now for 357sig, which is supposed to headspace on the case mouth, I have intentially overcrimped (RCBS dies) an empty case and it puts a nice profound roll on the case mouth. Also I have shaved down an empty case with a case trimmer, and the case seems to headspace properly on the bottleneck. So, since I am paranoid about bullet setback in 357sig, a couple of months ago I ordered one of those C&H canelure makers (the price on the ebay link above seems $20.00 or more to high). Just a few evenings ago, to keep calm and focused during evening of election day, I turned out the first set of test rounds with hornaday plated flat point bullets. The canelure maker works fine. Soon as I get a chance I'll see if there is any difference in accuracy with and without canelure. But to answer the question, I would say no problem to use taper crimp dies with a canelured bullet. However I would think roll crimp dies would only work properly with a canelured bullet; what ya gonna roll the lip into if there aint no groove in the bullet? That's my story, and I'm sticking to it. - shu __________________ If you would have Liberty you must accept that individual security is not the responsiblity of government. You must. - XAVIER ONASIS Last edited by shu; November 6, 2008 at 10:25 PM.

November 7, 2008, 02:34 PM	#11
TEDDY Junior member Join Date: December 10, 2006 Location: MANNING SC Posts: 837	roll crp I roll crimp all my pistol bullets.some have channels and some dont.what did shooters do before taper crimp???any one wonder.I dont heaspace on mouth of 45.as far as I am aware I head space on face of slide.slide drives case in to chamber and stops.the bullet is jammed into chamber.my loads will keep in the X ring at 50 ft.and at 50 yds will do the same.now ball factory loads are different.

November 1, 2008, 09:28 PM	#2
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"I assume that they can but if so, should be done lightly?" You are correct. Even if you are a Yankee.

November 1, 2008, 11:16 PM	#3
TFL4L Member Join Date: October 8, 2004 Posts: 45	I don't know about other dies, but the Lee Factory Crimp die is safe to use even with non-cannelured bullets.

November 2, 2008, 01:01 PM	#4
SwampYankee Registration in progress Join Date: November 1, 2008 Location: I can be found on a number of other forums. Posts: 1,333	I am using all RCBS equipment that I have scratched together. I have put a taper crimp on both .40 S&W and .38 bullets without cannelures but I was worried that 1) it might increase pressures excessively or 2) it might damage the bullets. The RCBS dies will taper crimp non-cannelured bullets and I have not seen any of the aforementioned symptoms, but this particular question is not addressed in any of the reloading manuals I have.

November 2, 2008, 03:46 PM	#6
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	In addition to the above, autoloader handguns headspace off the case mouths so they must have taper crimps. If we roll crimp them, or even do heavy taper crimps, it can easily allow the mouth to slid past the end of the chamber a small amount. If the case is too far forward it can cause misfires because of weak firing in impact. In theory, it could also cause pressues to climb significantly because the case mouth can't fully release the bullets.

November 2, 2008, 06:04 PM	#7
Loader9 Senior Member Join Date: July 29, 2008 Posts: 949	There's also the option of putting a cannelure on the bullet where you want it. I have a tool by C-H very similar to this on FleaBay. http://cgi.ebay.com/Cannelure-Tool-f...em370096288025 I put cannelures on bullet all the time. If I'm reloading some 38-40, I need a cannelure but no jacketed bullets available so I put a cannelure on a 40 SW 180gr XTP and call it good. You can do it with all types of bullets including ones that already have cannelures but not in the right spot for your particular gun. It's something to consider if you get into old cartridges or specialty cartridges.

November 3, 2008, 11:09 PM	#8
SwampYankee Registration in progress Join Date: November 1, 2008 Location: I can be found on a number of other forums. Posts: 1,333	I know this is going to sound dumb, but how to you tell you dies are roll crimping or taper crimping? I have assumed that mine are taper crimping, but how would I know?

November 5, 2008, 07:02 AM	#9
SwampYankee Registration in progress Join Date: November 1, 2008 Location: I can be found on a number of other forums. Posts: 1,333	Just a follow up, after some research I have discovered that apparently all RCBS dies are roll crimping, unless they are marked "TC" for taper crimp. I thought the TC was for tungsten carbide!