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Originally posted by steve4102:

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As has been stated on this sight many times. The use of the Lee Factory Crimp can be negated by reducing the decapping stem on your Lee Die by .002".that will give you a good and consistant holding pressure with no damage to the bullet head.
I understand Lee will supply undersize stems if requested.jc

I have a couple sets of Redding Type S bushing dies. I have tested different amounts of neck tension in my Browning BAR and Ruger Mini-30. I started with .001 neck tension and worked my up to .006 in .001 increments.

I tested for accuracy and bullet creep. Long story long, neck tension alone could not hold the bullet as secure as the LFCD. Accuracy with various amounts of neck tension were compared to my standard of .002 neck tension and a Med-Light crimp. I don't have the figures in front of me, but if memory serves me right, with .001-.003 neck tension accuracy was acceptable and very close to the LFCD with a slight advantage to the crimp. At .004 neck tension accuracy started to go down hill with .006 being down right horse shit.

In my tests and my rifles, no amount of neck tension can accomplish what the LFCD can. YMMV.

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Originally posted by steve4102:
Let us not forget the accuracy test done by the owners of this site. It showed improved accuracy with the use of the LFCD.
http://www.accuratereloading.com/crimping.html

Of course they are not "Idiots" and did not do the "Slamfire Smash" on the bullets.

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Originally posted by Grumulkin:

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Originally posted by SR4759:
If there is no cannuelure you get NO locking feature from the crimp. You are only pretending to crimp while damaging the bullet.

Yea; actually you DO get a locking feature from the crimp even without a cannelure. How do I know? I have shot a 460 S&W Magnum revolver using bullets with no cannelure. Without a crimp the bullets moved a lot with recoil and with a crimp with the Lee FCD die, they didn't move at all.

To recap things, in general I don't think a crimp improves accuracy in most cases but there are times when it is beneficial and/or needed in which cases a Lee FCD is the best method to crimp.

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The owner of this site has no background in statistics. He did not provide statistically significant prood of any such thing. He does not comprehend what the term means.

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Originally posted by steve4102:
There has been a few threads on here lately about the use of the Lee Factory Crimp die and how it affects accuracy. I tested the LFCD for accuracy quite some time ago and in my tests accuracy was improved. I have used it ever since on all of my semi-autos.

After reading through all the comments and posts on how the LFCD degraded accuracy I started to second guess myself and my previous testing, maybe I'm not getting the improved accuracy I thought I was.

I decided it was time double check my loads and see if crimp was actually helping or hurting.

Certainly none of this is scientific and probably not be enough of a sample to declare a winner or a looser, but it's what I got.

The rifle used was my Colt HBAR, 5.56. I used new never fired Lake city brass for this test as I thought it might be more consistent than my lot of several times fired LC brass.

This first target is Sierra 53gr HP MatchKing, 25.5gr AA 2520. The heavy crimp is "heavy" it put a deep cannulure in the bullet similar to some pictures that have been posted here in the past. The Med Light crimp was visible on a bullet bullet, but barely.



This load is 53gr Sierra with 26gr of 748. I fired five rounds at the "crimp" target first, then five at the "No-crimp" target



Same load, this time I fired five "no-crimp" first.



Same load, again I fired "no-crimp" first


That's all I got for now, you can draw your own conclusions, or not.

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Originally posted by steve4102:

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The owner of this site has no background in statistics. He did not provide statistically significant prood of any such thing. He does not comprehend what the term means.

How many rounds crimped vs no-crimp would you call significant? How many rifles would you call significant?

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Originally posted by SR4759:

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Originally posted by Grumulkin:

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Originally posted by SR4759:
If there is no cannuelure you get NO locking feature from the crimp. You are only pretending to crimp while damaging the bullet.

Yea; actually you DO get a locking feature from the crimp even without a cannelure. How do I know? I have shot a 460 S&W Magnum revolver using bullets with no cannelure. Without a crimp the bullets moved a lot with recoil and with a crimp with the Lee FCD die, they didn't move at all.

To recap things, in general I don't think a crimp improves accuracy in most cases but there are times when it is beneficial and/or needed in which cases a Lee FCD is the best method to crimp.

You use a custom die in a huge revolver that cannot resolve any accuracy differences between the crimped and uncrimped bullets. Has all of your defense of your position been based on this one die with this one revolver?
Perhaps you might do better to clean the cases and bullers more effectively. Could it be you have to use such a combo because you are using bright polished cases with a lubricant film that is not completely removed.
In any event I will never use such a die with bullets that do not have a cannelure in the proper place. You can claim it is all necessary for large rounds and such but Lee has to be idiots for suggesting crushing of bullets with a crimp die.

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Originally posted by SR4759:

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Originally posted by steve4102:

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The owner of this site has no background in statistics. He did not provide statistically significant prood of any such thing. He does not comprehend what the term means.

How many rounds crimped vs no-crimp would you call significant? How many rifles would you call significant?

Steve it is not me that deems anything statistically significant. It is the field of statistics. How big a confidence interval do you want? It is all in the text books.
Usually a statistically valid sample is between 25 and 30. That is not total.
That is one sample set versus another sample set in this case - not two sets of 12.
Then there is "What is a statistically valid number of shots for a group?" The various things I have seen written say a group of 7. I would prefer 10 shots per group and 20 would be much, much better. I believe the statistics is addressed in various military standards for ammunitions.

There are those that would protest due to time and cost constraints. But bear in mind when you start such testing that you do not know the answer so you design the experiment hoping that when you finish you have enough data to prove your hypothesis one way or the other.

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Check out the bench rest guys. NONE of them crimp a bullet with anything. If there was a chance of improved accuracy they would all crimp.

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Lord, the constant controversy about crimping or not will never end unless we agree it's just another part of what needs to be tried before we can know. For those who wish to crimp, the Lee FCDs are the best designs ever marketed.

Bringing in 'proof' tecniques from any competition event and willy-nilly applying it to hunting rifles is as silly as trying to apply tune up processes for a NASCAR engine to a Ford 4x4 F-350 diesel; that competition set up stuff won't matter because the devices are vastly different and they need different set-ups. Applying a bit of what used to be known as common sense helps.

One common sense failure is thinking basic 'instuctions' to set up anything is the end-all of it. Beginner instructions can only get us in the ball park; we can't ideally adjust a FL die or seater according to beginner instructions so why should we expect beginner instuctions will automatically work perfectly with a crimper? Many things about reloading are finess; instructions can get us close but it's up to us to make it right!

Pinch-waisted bullets like those in the photos above prove only one thing; the user vastly over did it. Blameing such damage on the crimper makes no more sense than saying my seater isn't making my "bullets" the right OAL!