To Crimp or Not to Crimp?

gregb

gregb

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I noticed Lee sells both 3 Die Rifle sets with Crimper and 2 Die Rifle Sets without the Crimping die.

My questions are: Do I have to crimp each round or can I loose this step and go with the 2 Die set. What are the advantages to crimping?

I'm just doing this for plinking and it will be for AR-15 (.223).
 
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Crimping is important for gun that are tube fed or very heavy recoiling.
Neck tension alone is adequate, and most often more consistent (accurate), than unnecessarily crimping.
R.
 
Revolvers with heavy bullets, tube fed big bore rifles, and rifles that recoil alot(big bores w/heavy bullets) all should have a firm roll crimp. The average cartridge used by folks on this site do not require it, IE: .308, 300Mag,.338mag., .375 Mag. etc.
 
Consistant neck tension is far more important than tight or hard. I have used the Lee Crimp die for several calibers including .308, .223 and 7.62x39mm. I have found there to be an accuracy difference, tighter more consistant groups in all three calibres.
Scott
 
pauls said:
http://ww w.accuratereloading.com/crimping.html

interesting read on a test someone performed on crimped vs. non and the effects on accuracy.
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No need to break the link, it's not a dealer/manufacturer site.
http://www.accuratereloading.com/crimping.html

Interesting Outcomes.
Ask any F-Class/Bench Rest/TR shooter if they crimp their loads. The answer will most likely be 100% NO across the board. Is there a reason for this? You can count on it that there is.
If Crimping increased accuracy in any of these disciplines, you can bet that every one of them would be doing it.

Something to think about anyway. :D
 
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The other way to accomplish the same result, perhaps better, is to remove the expander button from the decapping pin. This will give a lot more neck tension with no crimp variability due to case length. In my accuracy test in 308 (making Mexican Match) it cut group size dramaticaly vs. using a button.
 
Try it both ways. Guns with a long leade may benefit from a good crimp. I like the LEE factory crimp die, it lives up to its claims I think.
 
I just had a bullet (Nosler Partition) pull out of a case last week while I was moose hunting. I fired the first shot, reloaded in case of a follow up and when I tried to fire, nothing (I think I brushed the safety to half because there was no striker fall). When I cycled the action to see if I had short stroked the rifle what I got for my trouble was a case with no bullet ands powder everywhere. The bullet was stuck in the throat and took a good whack with a cleaning rod back at the house to get it out. Not sure what caused it as when I cycled the rest of my loads through the rifle back at the house I had no problems. Still, I think a little crimp wouldn't be a bad thing as the two cartridges that remained in the rifle after the shot did shorten up from hitting the front of the mag box.
 
That has been my experience as well. A proper crimp uniforms the bullet pull weight, and most folks will observe a small over all increse in accuracy. Any time that a bullet has a crimping gorrove and a short bearing surface, it is prudent to crimp. The .308 130 gr TSX comes to mind.
 
Any time that a bullet has a crimping gorrove and a short bearing surface, it is prudent to crimp. The .308 130 gr TSX comes to mind.
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From Barnes FAQ section on their site.

Do you recommend crimping your bullets?
We usually don’t recommend crimping our smaller-caliber bullets. However, if you choose to do so, a light crimp is best. Heavy caliber bullets (.375 and up) for large game require a heavy crimp, as do most revolver and lever-rifle loads.
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Check that data for the .30 caliber 130 gr TSX, the new Barnes manual recommends crimping it. I crimp all the TSX bullets I load, regardless of weight or caliber, and have good results across the board. A poor crimp is worse than no crimp at all, and this might be their concern.
 
I have never crimped my .308 reloads for my 700P, but I just started re-loading for my AR, and crimp these ones.I am firing dime-sized 5 shot groups at 100 yards, As its a 700P and the bullets are seated long, I load single shots anyways, so I wont be having any cycling issues with mine!
 
I believe the original poster mentioned shooting an AR-15 - crimping is really required for any semi-auto. I don't know why not crimping is even being suggested. The only way to eliminate using a third die step is to set your seating die low enough to seat and crimp in one pull.
 
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