Crimping for rifle rounds

w686mt · June 23, 2009, 11:51 AM

I have been reloading for a little less than a year. I load .223 in my AR15. Someone at the range told me that I should be crimping all my rounds as I reload. I have not been doing this and have had no problems. If there is anything that I should be doing I would like to know. I have read and heard about crimping other bullets but not rifle cartridges. Anyone with any advice, I will listen. I usually load Hodgden 335, 24gr with 55r Hornady FMJBT.

rgitzlaff · June 23, 2009, 01:04 PM

There is no good reason to crimp AR bullets, no one I know does it at my club. And there are a lot of really good high power shooters there that I know. I don't crimp when loading for my M1 garand .30-06 either, and haven't had a problem after many hundreds of rounds.

30Cal · June 23, 2009, 01:30 PM

You can, but assuming your dies aren't messed up, you shouldn't have to. Check and see if they grow/shrink a bunch (more than 5 or 10 thou) when you chamber them.

Scorch · June 23, 2009, 01:43 PM

Crimping in rifle cartridges is generally used to prevent bullet setback in tube-magazine rifles, or bullets "walking" out of the case in full auto or heavy recoiling rifles. The AR-15 is neither one of those, so I would say you don't need to crimp.

HJ857 · June 23, 2009, 01:52 PM

Just out of curiosity, what's the worst that can happen if you crimp? Also, what's the worst that can happen if you don't?

brickeyee · June 23, 2009, 02:35 PM

Quote:

Just out of curiosity, what's the worst that can happen if you crimp?

Accuracy is reduced.

Quote:

Also, what's the worst that can happen if you don't?

If you have inadequate neck tension you could set a bullet back during feeding and raise pressures.

Qtiphky · June 23, 2009, 05:45 PM

Contrary to what has been said, the opposite effect happened with my loads. My accuracy and consistency increased when shooting out of my AR platform after I used a Lee Factory Crimp die for .223. I don't crimp my hunting rounds for 270, 308 or 300 WSM, but for my 223 I do and it did improve accuracy.

sneaky pete · June 23, 2009, 07:52 PM

old Sneaky Pete here: as above--I don't crimp. I'm reloading 5.56/.223 , 6.5X55 Swed and 8MM mauser, I use Forster Ultra Micro. seaters for the .223 and 6.5 Swed and when I 1st seat I then rotate the bullet 180 degrees and re-seat. I find that I can keep my "Runout" to 0.002" or less using this method. With the 8MM mauser--just a Lee seating die and who cares. I had bought a Lee Crimp die for the .223 and the 6.5 Swed when I was using only Lee seating dies but when I went to the Forster Ultra Micro seaters I found that the Crimp step was a waste of time. I've also got an m1 Garand and when/if I ever run out of Greek HXP 30-06 and I start reloading '06 Maybe I'll crimp????THANX--SNEAKY

Slamfire · June 23, 2009, 08:31 PM

Quote:

Someone at the range told me that I should be crimping all my rounds as I reload. I have not been doing this and have had no problems.

Don't fix what ain't broke!

The "someone at the range" is an excellent example of bad advice.

This is what happens to 6.5 SMK overcrimped in a Lee Factory Crimp Die.
Why mess up good bullets with crimping?

HiBC · June 24, 2009, 03:40 PM

It might be fair to say it is controverial.
Like the majority here ,I do not crimp rifle rounds and all has been fine.However,the statement that a bullet setback in feeding will raise pressures is also true.If your 55 gr fmj's have a knurled cannelure,a light crimp won't hurt anything.
IMO,if the bullet does not have a cannelure,it is not designed to have a crimp.The cannelure gives a crimp somewhere to go.Without it,it is a tossup as to whether the Jacket will be bent in,as in the pix above,or the shoulder will try to collapse from the extra force required to crimp into a solid bullet.
Shoulder collapse would change headspace and likely increase case dia at the shoulder(My case is stuck in the chamber?)

For better info,most bullet mfg's have a phone number for tech questions.I suggest you listen to them before you listen to me!!

James R. Burke · June 24, 2009, 03:43 PM

Measure one real good. Load up so it is the last one in. Shoot the mag except for the one you measured. Take it out and measure it again. Sounds like over kill but you will know if it moved or how much.

jaguarxk120 · June 24, 2009, 04:11 PM

Maybe when you squash the hell out of the center section of a bullet it reduces friction or drag going down the bore.

Maybe like the Herters Wasp-Waist Sonic bullets of old? My Herters catalog is from 1976 and they are not listed, but memory serves me the bullets would kill at extremily loooong ranges and put 10 shots into one hole. Herters stuff was world famous or perfect, I think that was one of their trade marks

!!

steve4102 · June 24, 2009, 06:06 PM

This is what the experts at Sierra have to say about neck tension and crimping for an auto-loading service rifle.

"When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well.
To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension."

I load for several auto loaders and have done a whole lot of testing on crimping with the Lee Factory Crimp Die vs increasing neck tension. I have found that in all cases increasing neck tension destroys accuracy were as using a light to medium crimp with the LFCD increases accuracy or does nothing at all as far as accuracy is concerned. Never have I had the LFCD destroy or decrease accuracy. I have also found that A light to medium crimp will hold the bullet in place during the cycling of the action when as much as .008 neck tension will not.
Bottom line, if you want to secure your bullets in place and increase accuracy ate the same time, purchase a Lee Factory Crimp Die and use it.

bustoff · June 24, 2009, 07:51 PM

in steve4102 post there a mention of neck tension. if you dont want to crimp a easy way to increase neck tension is to take the expander out of the die and put it in your drill then get some 400 grit emery and polish expander.check progress with your mike or calipers.

sneaky pete · June 24, 2009, 10:00 PM

old Sneaky back-- Steve4102 referred to Sierra's position and we have to remember about "Liability"(lawyer-speak)--If they say it they're liable for it.. But I had a thought as I don't crimp. As I stated above I Full length size my .223 and seat to full magazine length with the Forster Ultra Micro Seater---But failed to mention that I only use Hornady 55gr "V-Max MOLY" projectiles(MOLY makes those projetiles Really slippery inside the case neck)--SO--go with me on this--possibly when the cartridge comes to a sudden stop does the projetile slide forwad till it comes to rest against the Lands???? and if so is that why my best 10 shot group @ 100 supported is 0.378". I know some Benchrest shooters seat to just touching the lands. Am I increasing my accuracy un-intended by NOT seating??? WOW what a consept! THANX--SNEAKY

HJ857 · June 25, 2009, 08:34 AM

I have limited experience with lawyers, but I've been told that most legal disclaimers are the result of a previous lawsuit. So you could assume that the lawsuit happened for exactly the same reason stated by the disclaimer.

My original question was rhetorical, I already know my level of comfort on this issue.

If I'm loading for my M4 format rifle, I always crimp and never worry about the rounds behaving properly. That rifle is not a benchrest rifle and was never intended to be such and I don't use it like it's a benchrest rifle.

If I'm loading for my match rifle, I agree with Steve4102's findings, proper crimp doesn't hurt accuracy. I also agree with disclaimers, I can learn from other's experiences, I don't need to re-invent the wheel.

.45 COLT · June 25, 2009, 08:57 AM

Something I've found in pistol rounds, and I would guess that it would hold true for rifle, is that a crimped load has a considerably higher MV than the same round left uncrimped. Some .38 Special rounds were 300 FPS different, some .45 Colt rounds were 250 FPS.

DC

wncchester · June 25, 2009, 09:05 AM

"I have not been doing this and have had no problems. "

Your range friend is wrong, if you have no problems you don't need to do it.

The Lee FCD is an excellant crimper, the best of its type in the opinon of many shooters. If it's used incorrectly, as is clearly illustrated in the photos above, it can, like anything else, do more harm than good.

sneaky pete · July 10, 2009, 05:46 PM

old sneaky pete back finally: I finally got aholt of a buddy of mine who's a permanent party civilian working in the Handloading section and Shooting and Winning for the USAMU and I asked hin about crimping and he told me that the AMU does NOT crimp any match bullets that the crimping of military bullets is related to military functions--mainly Auto firing and the competition teams don't use crimped bullets and they do check Run-out and their standard is 0.002'" or less. Crimp if you want but if you aren't involved with a lot of full-auto firing seems like a waste of time. at least thats the position at he AMU and Old Sneaky's too. THANX--SNEAKY

June 23, 2009, 11:51 AM	#1
w686mt Junior Member Join Date: June 23, 2009 Posts: 5	Crimping for rifle rounds I have been reloading for a little less than a year. I load .223 in my AR15. Someone at the range told me that I should be crimping all my rounds as I reload. I have not been doing this and have had no problems. If there is anything that I should be doing I would like to know. I have read and heard about crimping other bullets but not rifle cartridges. Anyone with any advice, I will listen. I usually load Hodgden 335, 24gr with 55r Hornady FMJBT.

June 23, 2009, 01:30 PM	#3
30Cal Senior Member Join Date: December 3, 2002 Posts: 1,264	You can, but assuming your dies aren't messed up, you shouldn't have to. Check and see if they grow/shrink a bunch (more than 5 or 10 thou) when you chamber them. Last edited by 30Cal; June 23, 2009 at 02:43 PM.

June 23, 2009, 01:43 PM	#4
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	Crimping in rifle cartridges is generally used to prevent bullet setback in tube-magazine rifles, or bullets "walking" out of the case in full auto or heavy recoiling rifles. The AR-15 is neither one of those, so I would say you don't need to crimp. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

June 23, 2009, 07:52 PM	#8
sneaky pete Senior Member Join Date: November 24, 2004 Location: Florida Keys Posts: 510	NO crimp for Sneaky! old Sneaky Pete here: as above--I don't crimp. I'm reloading 5.56/.223 , 6.5X55 Swed and 8MM mauser, I use Forster Ultra Micro. seaters for the .223 and 6.5 Swed and when I 1st seat I then rotate the bullet 180 degrees and re-seat. I find that I can keep my "Runout" to 0.002" or less using this method. With the 8MM mauser--just a Lee seating die and who cares. I had bought a Lee Crimp die for the .223 and the 6.5 Swed when I was using only Lee seating dies but when I went to the Forster Ultra Micro seaters I found that the Crimp step was a waste of time. I've also got an m1 Garand and when/if I ever run out of Greek HXP 30-06 and I start reloading '06 Maybe I'll crimp????THANX--SNEAKY

June 24, 2009, 04:11 PM	#12
jaguarxk120 Senior Member Join Date: February 28, 2008 Location: Michigan Posts: 2,619	Maybe when you squash the hell out of the center section of a bullet it reduces friction or drag going down the bore. Maybe like the Herters Wasp-Waist Sonic bullets of old? My Herters catalog is from 1976 and they are not listed, but memory serves me the bullets would kill at extremily loooong ranges and put 10 shots into one hole. Herters stuff was world famous or perfect, I think that was one of their trade marks!! Last edited by jaguarxk120; June 24, 2009 at 04:19 PM.

June 23, 2009, 01:04 PM	#2
rgitzlaff Senior Member Join Date: January 8, 2006 Location: Madison, WI Posts: 524	There is no good reason to crimp AR bullets, no one I know does it at my club. And there are a lot of really good high power shooters there that I know. I don't crimp when loading for my M1 garand .30-06 either, and haven't had a problem after many hundreds of rounds.

June 23, 2009, 01:52 PM	#5
HJ857 Senior Member Join Date: January 9, 2007 Posts: 447	Just out of curiosity, what's the worst that can happen if you crimp? Also, what's the worst that can happen if you don't?

June 23, 2009, 05:45 PM	#7
Qtiphky Senior Member Join Date: December 11, 2008 Location: Upper Michigan, above the Mackinac Bridge Posts: 568	Contrary to what has been said, the opposite effect happened with my loads. My accuracy and consistency increased when shooting out of my AR platform after I used a Lee Factory Crimp die for .223. I don't crimp my hunting rounds for 270, 308 or 300 WSM, but for my 223 I do and it did improve accuracy.

June 24, 2009, 03:40 PM	#10
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,283	It might be fair to say it is controverial. Like the majority here ,I do not crimp rifle rounds and all has been fine.However,the statement that a bullet setback in feeding will raise pressures is also true.If your 55 gr fmj's have a knurled cannelure,a light crimp won't hurt anything. IMO,if the bullet does not have a cannelure,it is not designed to have a crimp.The cannelure gives a crimp somewhere to go.Without it,it is a tossup as to whether the Jacket will be bent in,as in the pix above,or the shoulder will try to collapse from the extra force required to crimp into a solid bullet. Shoulder collapse would change headspace and likely increase case dia at the shoulder(My case is stuck in the chamber?) For better info,most bullet mfg's have a phone number for tech questions.I suggest you listen to them before you listen to me!!

June 24, 2009, 03:43 PM	#11
James R. Burke Senior Member Join Date: January 3, 2009 Location: U.P. of Mich/Quinnesec Posts: 1,897	Measure one real good. Load up so it is the last one in. Shoot the mag except for the one you measured. Take it out and measure it again. Sounds like over kill but you will know if it moved or how much.

June 24, 2009, 06:06 PM	#13
steve4102 Senior Member Join Date: December 23, 2005 Location: Minnesota Posts: 2,952	This is what the experts at Sierra have to say about neck tension and crimping for an auto-loading service rifle. "When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it. There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension." I load for several auto loaders and have done a whole lot of testing on crimping with the Lee Factory Crimp Die vs increasing neck tension. I have found that in all cases increasing neck tension destroys accuracy were as using a light to medium crimp with the LFCD increases accuracy or does nothing at all as far as accuracy is concerned. Never have I had the LFCD destroy or decrease accuracy. I have also found that A light to medium crimp will hold the bullet in place during the cycling of the action when as much as .008 neck tension will not. Bottom line, if you want to secure your bullets in place and increase accuracy ate the same time, purchase a Lee Factory Crimp Die and use it.

June 24, 2009, 07:51 PM	#14
bustoff Member Join Date: June 7, 2009 Posts: 32	in steve4102 post there a mention of neck tension. if you dont want to crimp a easy way to increase neck tension is to take the expander out of the die and put it in your drill then get some 400 grit emery and polish expander.check progress with your mike or calipers.

June 24, 2009, 10:00 PM	#15
sneaky pete Senior Member Join Date: November 24, 2004 Location: Florida Keys Posts: 510	Another mindset about Not crimping! old Sneaky back-- Steve4102 referred to Sierra's position and we have to remember about "Liability"(lawyer-speak)--If they say it they're liable for it.. But I had a thought as I don't crimp. As I stated above I Full length size my .223 and seat to full magazine length with the Forster Ultra Micro Seater---But failed to mention that I only use Hornady 55gr "V-Max MOLY" projectiles(MOLY makes those projetiles Really slippery inside the case neck)--SO--go with me on this--possibly when the cartridge comes to a sudden stop does the projetile slide forwad till it comes to rest against the Lands???? and if so is that why my best 10 shot group @ 100 supported is 0.378". I know some Benchrest shooters seat to just touching the lands. Am I increasing my accuracy un-intended by NOT seating??? WOW what a consept! THANX--SNEAKY

June 25, 2009, 08:34 AM	#16
HJ857 Senior Member Join Date: January 9, 2007 Posts: 447	I have limited experience with lawyers, but I've been told that most legal disclaimers are the result of a previous lawsuit. So you could assume that the lawsuit happened for exactly the same reason stated by the disclaimer. My original question was rhetorical, I already know my level of comfort on this issue. If I'm loading for my M4 format rifle, I always crimp and never worry about the rounds behaving properly. That rifle is not a benchrest rifle and was never intended to be such and I don't use it like it's a benchrest rifle. If I'm loading for my match rifle, I agree with Steve4102's findings, proper crimp doesn't hurt accuracy. I also agree with disclaimers, I can learn from other's experiences, I don't need to re-invent the wheel.

June 25, 2009, 08:57 AM	#17
.45 COLT Senior Member Join Date: May 18, 2004 Posts: 308	Something I've found in pistol rounds, and I would guess that it would hold true for rifle, is that a crimped load has a considerably higher MV than the same round left uncrimped. Some .38 Special rounds were 300 FPS different, some .45 Colt rounds were 250 FPS. DC

June 25, 2009, 09:05 AM	#18
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"I have not been doing this and have had no problems. " Your range friend is wrong, if you have no problems you don't need to do it. The Lee FCD is an excellant crimper, the best of its type in the opinon of many shooters. If it's used incorrectly, as is clearly illustrated in the photos above, it can, like anything else, do more harm than good.

July 10, 2009, 05:46 PM	#19
sneaky pete Senior Member Join Date: November 24, 2004 Location: Florida Keys Posts: 510	What does the US Army Marksmanship unit do??? old sneaky pete back finally: I finally got aholt of a buddy of mine who's a permanent party civilian working in the Handloading section and Shooting and Winning for the USAMU and I asked hin about crimping and he told me that the AMU does NOT crimp any match bullets that the crimping of military bullets is related to military functions--mainly Auto firing and the competition teams don't use crimped bullets and they do check Run-out and their standard is 0.002'" or less. Crimp if you want but if you aren't involved with a lot of full-auto firing seems like a waste of time. at least thats the position at he AMU and Old Sneaky's too. THANX--SNEAKY