Accuracy vs Crimping - The Firearms Forum

steve4102 · 10-01-2012, 10:18 PM

I know I have posted my accuracy tests using the Lee Factory Crimp die in the past, so I hope you don't mind if I do it again.

I purchased a K of Midsouth's 55gr Varmint Nightmare JHP bullets for about $90.

I decided to test this new to me bullets in my Colt AR both with a Lee crimp and without. My crimp is what I call a Med-Light.

I chose Win 748 as it has worked well for me in the past with 50-55gr bullets.

I fired five rounds at each target allowing the barrel to cool between each five round group. This is the first set of groups.

I then fired five shot groups from the bottom up starting at 26.5gr and working up the target to 25gr. I did not let the barrel cool at all. The only down time between rounds was loading the mag.

As you can see these bullets shoot damn good for cheap bullets and you can see that the rounds crimped with the LFCD outperformed the non crimped rounds.

26gr Crimped is a winner in my book.

JLA · 10-01-2012, 10:50 PM

And you have a real winner with 25.5-26 gr W748 and those bullets. ID personally call 25.8 my load.

Good thread steve.

woolleyworm · 10-01-2012, 11:12 PM

I'll second the thumbs up! Great visual documentation and clear results. The LFCD is worth the extra effort.

aa1911 · 10-02-2012, 12:58 AM

thanks for the good write up!

isn't 748 the same powder used in military ammo for the 5.56? thought I read that somewhere recently.

Hodgen has their new .223 specific powder out now too, supposed to be even cleaner burning and 'cooler'/easier on the barrels. but the military stuff burns just fine as far as I care.

myfriendis410 · 10-02-2012, 09:30 AM

What was your distance?

A crimp can certainly improve consistent velocity numbers which (usually) make for a more accurate load.

Nice workup.

steve4102 · 10-02-2012, 09:48 AM

Sorry forgot that, 100 yards

JLA · 10-02-2012, 07:50 PM

Quote:

Originally Posted by aa1911

thanks for the good write up!

isn't 748 the same powder used in military ammo for the 5.56? thought I read that somewhere recently.

Hodgen has their new .223 specific powder out now too, supposed to be even cleaner burning and 'cooler'/easier on the barrels. but the military stuff burns just fine as far as I care.

As far as I understand milspec 5.56 ammo is loaded with bulk grade W748. It was developed for longer barrel life in the M16s and increased performance.

And that CFE223 your are referring to. Awesome stuff. it prevents copper fouling. Burn speed is close to W748.

bluesea112 · 10-03-2012, 03:55 PM

I have always heard that crimping is better for accuracy, but it is nice to see it proven on paper.

Bindernut · 10-03-2012, 06:18 PM

Very nice documentation Steve!
Just out of curiosity, but I notice how on-target the groups are. You didn't have any major POI change through that range of charge weights? I haven't ladder tested my .223 yet.

To date, I haven't messed around with the LFCD in any caliber.
I have picked a couple calibers up when they've been on sale but I honestly have never threaded them into a press yet.

I'll have to put forth a little more effort to give em a try some time.
I do use a crimp on any cannelured bullet for my rifle loads, but just what I get from the particular brand seating die that I'm using.

10-01-2012, 10:18 PM	#1
steve4102 Former Guest Join Date: Jan 2006 Location: Minnesota Contributor Posts: 2,760	Accuracy vs Crimping I know I have posted my accuracy tests using the Lee Factory Crimp die in the past, so I hope you don't mind if I do it again. I purchased a K of Midsouth's 55gr Varmint Nightmare JHP bullets for about $90. I decided to test this new to me bullets in my Colt AR both with a Lee crimp and without. My crimp is what I call a Med-Light. I chose Win 748 as it has worked well for me in the past with 50-55gr bullets. I fired five rounds at each target allowing the barrel to cool between each five round group. This is the first set of groups. I then fired five shot groups from the bottom up starting at 26.5gr and working up the target to 25gr. I did not let the barrel cool at all. The only down time between rounds was loading the mag. As you can see these bullets shoot damn good for cheap bullets and you can see that the rounds crimped with the LFCD outperformed the non crimped rounds. 26gr Crimped is a winner in my book. --> Last edited by steve4102; 10-01-2012 at 10:20 PM..

10-01-2012, 10:50 PM	#2
JLA TFF Moderator/Host Join Date: Feb 2007 Location: Heart Of Texas Contributor Posts: 17,319	Re: Accuracy vs Crimping And you have a real winner with 25.5-26 gr W748 and those bullets. ID personally call 25.8 my load. Good thread steve. __________________ It takes 43 muscles to frown, 17 to smile, and 3 for proper trigger squeeze. The latest caliber or gear is no substitute for experience and skill. Rifles and cartridges don't make hits -- shooters do. Fact of life: After Monday and Tuesday, even the calendar says WTF!

10-01-2012, 11:12 PM	#3
woolleyworm TFF Moderator/Host Join Date: Feb 2009 Location: SW Fort Worth Contributor Posts: 4,883	Re: Accuracy vs Crimping I'll second the thumbs up! Great visual documentation and clear results. The LFCD is worth the extra effort. __________________ . What are you gonna do, talk the alien to death? -- (on Sigourney Weaver's worry about Guns in Aliens) "Safety is something that happens between your ears, not something you hold in your hands." "I carry a small gun to compensate for my huge Blue press." .

10-02-2012, 12:58 AM	#4
aa1911 Advanced Senior Member Join Date: Dec 2010 Location: Pacific Northwest Posts: 3,115	Re: Accuracy vs Crimping thanks for the good write up! isn't 748 the same powder used in military ammo for the 5.56? thought I read that somewhere recently. Hodgen has their new .223 specific powder out now too, supposed to be even cleaner burning and 'cooler'/easier on the barrels. but the military stuff burns just fine as far as I care. __________________ "Loud noises don't end gunfights.... well placed shots do."

10-02-2012, 09:30 AM	#5
myfriendis410 Senior Member Join Date: Mar 2011 Location: Lompoc California Posts: 543	Re: Accuracy vs Crimping What was your distance? A crimp can certainly improve consistent velocity numbers which (usually) make for a more accurate load. Nice workup. __________________ Life's too short to shoot an ugly gun.....

10-02-2012, 09:48 AM	#6
steve4102 Former Guest Join Date: Jan 2006 Location: Minnesota Contributor Posts: 2,760	Re: Accuracy vs Crimping Sorry forgot that, 100 yards

10-03-2012, 03:55 PM	#8
bluesea112 Advanced Senior Member Join Date: Nov 2005 Location: West, TX Contributor Posts: 1,257	Re: Accuracy vs Crimping I have always heard that crimping is better for accuracy, but it is nice to see it proven on paper.

10-03-2012, 06:18 PM	#9
Bindernut Advanced Senior Member Join Date: Oct 2007 Location: ND, USA Posts: 2,453	Re: Accuracy vs Crimping Very nice documentation Steve! Just out of curiosity, but I notice how on-target the groups are. You didn't have any major POI change through that range of charge weights? I haven't ladder tested my .223 yet. To date, I haven't messed around with the LFCD in any caliber. I have picked a couple calibers up when they've been on sale but I honestly have never threaded them into a press yet. I'll have to put forth a little more effort to give em a try some time. I do use a crimp on any cannelured bullet for my rifle loads, but just what I get from the particular brand seating die that I'm using. Last edited by Bindernut; 10-03-2012 at 06:21 PM..