leee factory crimp for 308


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jack44
January 5, 2012, 08:30 PM
I was thinking about maybe I should sart crimping my 308 rounds now,since some people say it gives better accuracy WHAT DO YOU THINK?.

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rcmodel
January 5, 2012, 08:40 PM
Tell them to prove it!

You don't see benchrest champions, or 1,000 yard gold medal winners crimping anything now do you?

rc

Blue68f100
January 5, 2012, 09:08 PM
since some people say it gives better accuracy WHAT DO YOU THINK?.

Yhea, the ones selling the die's. And the ones who do not know how to set their dies up correctly.

Don't waste you money.

243winxb
January 5, 2012, 09:15 PM
I like neck tension. No crimp for me.

wingman
January 5, 2012, 10:34 PM
I reloaded 40+ years never crimped a round for rifles however recently I purchased an AR worked up some good loads with acceptable accuracy I had a lee FCD die in 223 so thought why not crimp(very light)every third group in my tray, funny thing is the crimped rounds were more accurate.

My suggestion is try it may work may not,can't hurt.

So it gives me a new project testing crimped rounds in my bolt guns.;)

Note: Bench rest shooters are using custom chambers/dies.

jack44
January 5, 2012, 10:56 PM
thanks- I guess I will save my money

35 Whelen
January 5, 2012, 11:43 PM
Tell them to prove it!

You don't see benchrest champions, or 1,000 yard gold medal winners crimping anything now do you?



Perfectly said!!

35W

Hondo 60
January 6, 2012, 12:22 AM
When I bought my AR I also bought a book called "The AR-15" by Patrick Sweeney.
He did a test of crimp vs no-crimp.
The crimped one were more accurate.

My own test has confirmed his.
It might or might not help you.
It isn't going to hurt to try.

I also think wingman said it right
Note: Bench rest shooters are using custom chambers/dies.

Are you?

res7s
January 6, 2012, 03:12 AM
Every gun is different. You won't know until you try it.

dirtengineer
January 6, 2012, 03:15 AM
Best bet for accuracy is probably fire formed and neck resize only, no factory crimp. I factory crimp loads in semi auto and my hunting ammo because the ammo may be rough handled.

chris in va
January 6, 2012, 05:41 AM
The FCD for rifle calibers has been shown to tighten up the velocity variances.

I just do it for my 223's to prevent any setback through my AR.

steve4102
January 6, 2012, 10:06 AM
You don't see benchrest champions, or 1,000 yard gold medal winners crimping anything now do you?

True, but I don't see BR shooters using off the self sporting rifles like mine either. Does that mean I shouldn't use them as well.
I do see BR shooters using techniques that hunters and sport shooters don't or can't use in their off the shelf hunting rifles, things like pig jamming the bullet into the lands, indexing each and every round, loading single shot in an AR, custom chambers so tight that resizing the neck is not needed, etc. You know things like this that take the place of a Lee Factory Crimp Die.

Back to the OP, the LFCD works for me. I have run extensive test with and without the crimp in several rifles with neck tension from .001 to as much as .006. Al;l my rifles show increased accuracy with the use of the LFCD. YMMV

zeke
January 6, 2012, 10:25 AM
Depends on bullet used, rifle used, purpose of load etc. Am using a lfc on all my rifle rounds, but most rounds very lightly. It is used a little heavier on rounds for semi autos, especially with bullets with minimal bearing surface and a crimp cannulure.

It is possible to use a lfc so hard sd is practically non-existent, but accuracy is also non existent.

Cmeboston
January 6, 2012, 10:47 AM
I don't crimp my .308 for my M1A. Neck tension is adequate for me

mtrmn
January 6, 2012, 05:39 PM
I use the Lee FCD on 308 and 223 because all I shoot them through is AR's and don't trust the neck tension only to keep bullets from being set back during cycling. I crimp them LIGHTLY, not the full gorilla grip crimp the die is capable of. If your shooting a bolt gun no need to crimp. But as others have said, it might help accuracy.

gamestalker
January 7, 2012, 12:49 AM
Crimping bottle necks, not in my life time. I only crimp my magnum wheel gun stuff. I've never even had a tubular magazine round that neck tenson alone wouldn't mainatin consistent OAL.

Bigdog57
January 7, 2012, 06:54 PM
I do crimp my .308Win and 7.62X51, as the 7.62 will be used in the CETME (the .308 could be, in an emergency). Don't want to chance bullet setback.
My personal load of .308Win using 165 grain bullet crimped gives me three bullets touching in a neat cloverleaf at 100 yards in my 'new-to-me' Remington Model Seven - I'll stay with what works for ME.
I do also crimp my .223Rem and 5.56X45 loads for the same reasons - reliability in a semiauto.

I do not crimp my .22 Hornet loads for my singleshot rifle...... :)

SlamFire1
January 8, 2012, 05:05 PM
When I bought my AR I also bought a book called "The AR-15" by Patrick Sweeney.
He did a test of crimp vs no-crimp.
The crimped one were more accurate.
Bad information does not become better just because it is in print.

Crimping bullets can and does deform the jacket, and does deform the soft lead core. Just press on lead, it does not spring back at all. Crimping causes damage underneath the jacket that you cannot see. Deforming the core changes the center of balance and the center of gravity. Move the center of gravity and the bullet will wobble and oscillate in flight.

Put it to you this way, we have the most perfect bullets ever. They have the most consistent jackets, best weight distributions, in the history of man.

So how does swaging them in the middle improve things?

It does not.

6.5 mm SMK's overcrimped with a Lee Factory Crimp Die.

http://img.photobucket.com/albums/v479/SlamFire/Reloading/ReducedLeeCrimped65SMK.jpg


Only crimp for elephant guns, those things have so much recoil that bullet will come out of case necks.

Only crimp for cartridges used in chain guns, like Vulcan cannons. The high ramming speeds can cause the bullets to pop out of the case necks.

Only crimp for rifles with tubular magazines, assuming recoil pushes the bullet in the stack further in.

I do taper and roll crimp pistol cartridges. I consider pistols to be spitting distance weapons and pistols function just fine with crimps.

rcmodel
January 8, 2012, 05:14 PM
"The AR-15" by Patrick SweeneyDon't quote me on the exact number.

But Patrick Sweeney once wrote a magazine article in which he claimed to have shot something like 10,000 rounds in a handgun torture test.

In one day.
By himself.

Friends, that right there is an average of 21 rounds a minute, for 8 hours straight!
And he loaded his own magazines!

rc

J_McLeod
January 8, 2012, 08:03 PM
I have the deluxe die set, and decided to see if the crimp was worth it for my AR. So I loaded two batches of ammo, each with a 55gr FMJ, 25.3gr of Varget and a 2.244 OAL. Everything was the same except on batch got crimped and the other didn't. Here are the results, crimped rounds on the left uncrimped on the right. This was only 5 rounds each through my rifle, your results may vary.

Curator
January 8, 2012, 09:00 PM
The Lee Factory crimp (collet-type) die is regularly panned on this and other forums. However, It can often make a large positive difference in accuracy when used correctly. Ovbiously the examples of overcrimping are not what you need to do. A Lee Factory crimp correctly applied can reduce shot to shot variation significantly by increasing the pressure at which the bullet begins to leave the case. The factory crimp can increase accuracy in rifles with a large throat by keeping the bullet centered in line with the bore as it enters into the rifling. This is often the case with older military rifles and some magnums that are made with a long "free-bore." Any tool is only as good as the guy who is using it. If you are shooting a bolt action match rifle you probably will be better off without a crimp. With many other types of firearms the Lee Factory crimp die can be a real advantage.

SlamFire1
January 9, 2012, 10:52 AM
Ovbiously the examples of overcrimping are not what you need to do.

Agree, the bullet picture I have shown is an extreme example. However following the Lee crimp die instructions I loaded an ammo can of 308 match ammunition. Later I pulled the bullets and found many examples of ‘coke bottled” bullets. The crimp on the case neck did not leave any external marks and yet the crimping force was sufficient to swage match bullets in the middle.

You cannot tell if you are damaging your bullets until you pull your bullets, and I will bet for some examples, you will have to section the bullet to show the separation of core from jacket.

A Lee Factory crimp correctly applied can reduce shot to shot variation significantly by increasing the pressure at which the bullet begins to leave the case. The factory crimp can increase accuracy in rifles with a large throat by keeping the bullet centered in line with the bore as it enters into the rifling. This is often the case with older military rifles and some magnums that are made with a long "free-bore."

This is an unproven statement that reads as if it came from a marketing department.

Consistent neck pull is going to come from your sizing die. As for getting good accuracy with barrels with a lot of free bore, I don’t believe that any crimp die is going to help that or that any crimp die keeps the bullet centered once it leaves the case. The best you can do when your throat moves is to move the bullet out and try to find bullets that are not jump sensitive.

And for improving accuracy with older military rifles, “you can’t put in what God took out”. A crimp die is not going to improve what poor bedding and poor barrels took out.


When the National Champs I shoot with, pull targets with, start telling me how the Lee Factory Crimp die improved their groups, then I will believe it.

I am confident to state that to date, the number of National Championships won with rifle ammunition crimped by the Lee Factory Crimp Die is:

ZERO!

mtrmn
January 10, 2012, 03:29 PM
All these arguments to crimp or not to crimp are not convincing either side. :banghead: I crimp and I like it --bottom line. You don't crimp and you like it ---bottom line. No amount of argument will change that.

To the OP- all I can answer is try it and prove to yourself whether it makes a difference.

I crimp for the reason that I want the extra peace of mind shooting semi-autos-not for better accuracy, although I have not noticed an accuracy difference either way. BUT I'm not a match shooter.

No amount of all of us getting worked up on this forum because we can't convince the rest of the world that our way is the right way is going to prove anything and most of all will not help the OP get a real answer to his question.
The only way is for him to decide for himself. (It will also give him an excuse to do some extra loading/shooting-which is always good) Advice on how best to use the FCD might help him during his tests, but that's about all we can do for him. In the end he will have to decide if he likes crimping or not.
No hard feelings here--just my humble opinion.:)

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