When should you crimp?

[Squeaky 135]

Hey Guys:

 

I have a friend wanting to get into reloading and he has a simple question I don't know the answer to: when should you crimp rifle rounds?

 

I know you usually crimp pistol rounds, but I personally have never worried about crimping rifle rounds. I have reloaded for .30-06 and .30-30 without worrying about crimping. No problems. Those were very accurate rounds too.

 

However, my friend wants to start loading his own .223 and .308 cartridges. Am I correct in assuming he should crimp due to their semi-automatic actions?

 

My overall question is when is crimping needed? I feel silly admitting I've never really thought about it. When do you crimp, how much, and why? For example, I plan to reload .45-70 shells one day, but my .45-70 rifle is a single-shot Pedersoli Remington rolling block. So ... I'm not worried about crimping unless lead molded bullets require it.

 

Thanks. I'm just trying to keep things safe for me and my friend. I do not want to give incorrect advice. At the least, I don't want him to possibly suffer jamming issues because his cartridges' C.O.L.s aren't being maintained. At worst, I don't want his gun to blow up because a crimped bullet created excessive pressure. Curiously, this a potentially important detail about which I find myself honestly ignorant.

 

By the way, he hasn't loaded any rounds yet.

 

Am I on the right track guys?

 

Thank you!

 

 

 

 

 

[Rhodes1968 1,638]

I always crimp for consistency of chamber pressure. I use the Lee crimp die and it works very well.

 

Otherwise would crimp on a mag fed semi anyway, have seen boolits get pushed into the case a couple of times.

[zagumennyyilya 51]

I played with how much to crimp and the amount doesn't seem to affect my cycling of the action, unless i crimp not enough and the bullet gets pushed in, I have had that a few times. You cannot over crimp a case, not possible, at least on my lee die, there will be a mechanical bind that creates a minimum size of case mounth, if you adjust further, the crimp will crimp and stop at that minimum size. So dont worry about that, unless you are using some other crimp i am not aware of. The tightest possible crimp on my lee die does not blow up my rifle, and does not create excessive pressure. I just makes the start pressure the same for every bullet.

[JESS1344 508]

GUYS,

USED THOSE LEE FACTORY CRIMP DIES IN A NUMBER OF CALIBERS, THEY'RE GOOD GEAR, AND ESSENTIAL IN SOME CASES.

 

JESS1344

[Rhodes1968 1,638]

The only time I have not crimped is when I measure the chamber on a boltie.

 

And thats not a live round, I just load it and close the bolt then eject the round and measure.

[HB of CJ 1,263]

Excellent answers already given and thank you. We kinda crimp sometimes. Guess it depends upon the set back potential and what kind of gun you have. Sometimes we do not even full length resize if the handloads are dedicated to just one gun. An example; taper crimping the M1 Carbine case can be kinda trickly as the round headspaces on the case rim and case length/headspace is very critical with the M1 Carbine platform. I would say if you must, then do soss. If you do not have to, then perhaps not. Clear as mud. HB of CJ (old coot)

[Rhodes1968 1,638]

Unless I'm mistaken all commercial and mil-spec ammo is crimped in the same fashion as the Lee.

[nlacy 692]

1989. I believe that was the last year you could acceptably crimp. http://www.youtube.com/watch?v=_nVbDBzlsi4

 

 

and yes, I know I'm a dumb ass

Edited August 2, 2013 by mizombiekilla

[2manysaigas 14]

I also use the lee factory crimp die. Excessive crimp widens the spread, a little is good for accuracy as pressure builds prior to launch. Crimp just enough that you can not force the bullet back by pushing the tip of the bullet against the edge of your bench. I crimp some even on bolt guns.