to crimp, or not to crimp
 

I would like to know what you folks think about whether or not to crimp the bullet in the case. I think I understand the importance of crimp as far as bullet movement is concerned. ie; if the bullet isn' t crimped, then the bullets in the magazine may dislodge or move in their cases due to the recoil of the gun. Is this correct??

But, as far as accuracy is concerned, which is more accurate, crimped bullet, or un-crimped bullet?

RE: to crimp, or not to crimp
 

I' ve never seen where a crimped bullet was anymore accurate than one that wasn' t crimped. I' ve loaded both ways and tried this and the accuracy was unchanged with my guns. The only time i crimp now is if i' m loading for an automatic where the bullets will be stacked otherwise i don' t crimp.

RE: to crimp, or not to crimp
 

Crimping prevents the bullet from moving rearward into the cartridge case during recoil or any other action that may cause the bullet to move. If the bullet moves too far out of spec (either way), dangerous pressure may result during firing.

In terms of accuracy, I personally get the best results from uncrimped loads. I don' t crimp ANY of my bolt action rifle loads, for target or hunting purposes, but I do put a mild taper crimp onto all 308 Winchester I load for my brother' s semi-auto.

Anything going into a tubular magazine MUST be crimped.

RE: to crimp, or not to crimp
 

Unless you have a tubular magazine or are talking handguns crimping is totally unnecessary and offers no advantages.

RE: to crimp, or not to crimp
 

thank you, I appreciate the the quick answers. This website is awesome for just this reason. For some reason, my wife didn' t know what to do about crimping. :D
LOL

RE: to crimp, or not to crimp
 

We load for 38-55 ,40-65, 45-70 and find that crimping gives us a better burn on the powder and improved accuracy for this type rifle and slow powders . the only other thing we crimp for is tubular feed magazines . You can read all kinds of things pro and con but I believe the best answer is try both and form your own opinion .

RE: to crimp, or not to crimp
 

Thanks halcon,
I knew that I had read somewhere that crimping had something to do with accuracy, but couldn' t remember which was which.
Do you live anywhere close to Eugene, OR?

RE: to crimp, or not to crimp
 

I like crimping in some situations. One for my 300RUM. With new brass crimping is a waste of time. But after 3 firings, I see brass getting hardened, and neck tension go down. So my cure before trying to aneal or sell on ebay is to crimp. Seems to bounce those groups back under 1" . All I am doing is putting the neck tension back, I know.

RE: to crimp, or not to crimp
 

That' s interesting bigcountry, I never thought about the need for crimping as changing while using the same brass.
Do you crimp on a bullet that doesn' t have a " crimp groove?"

RE: to crimp, or not to crimp
 

MaineHunter I live about 45 miles south of Eugene in a very small town ,at least close to a small town ,I live in the country .
If you are going to crimp I would spend the money and buy the Lee Precisions crimp . Its the easiest to use and case length is not as critical , with a roll crimp you need a cannelured bullet and all the cases the same length . What caliber are you considering to use a crimp on .

RE: to crimp, or not to crimp
 

Mainehunt, I only crimp on the A-Frames or TBBC or Speer bullets in my 300RUM. This gun tends to really work the neck.

Really what my post says is I should anneal or buy new brass and forget about crimping but I do anyway. I have had success at crimping with the A-Frame.

RE: to crimp, or not to crimp
 

big country, thanks for the pointers, I really appreciate it.

Halcon, I am loading for the 300 Win Mag. 200 grain Sierra game king, 64 grains of IMR4350. The reason I asked about Eugene is because I have a sister who lives there. Heck of a ways from Maine. Her husband just shot a cow elk with a bow about 2-3 weeks back. I' m wicked jealous. :)

RE: to crimp, or not to crimp
 

Mainehunt There is good and bad things about every where , ask him when was the last time he went Moose hunting .Now I' m jealous , Have a good day halcon

RE: to crimp, or not to crimp
 

Halcon,
Yeah yuou' re right, grass is always greener ..........
Only problem with hunting moose in Maine is, I am a resident ,so I have about a 1 in 80 chance of " drawing" a moose permit. A NON-resident has about 1-10. These are round-about numbers. In other words, put in for a moose permit here and I' ll show you where to get one, because I' ve never been able to go :(

RE: to crimp, or not to crimp
 

I' ve found that using a Lee factory crimp die does slightly increase accuracy with several different cartridges I reload. I' ve never seen any improvement on rifle cartridges while crimping with a bullet seating die however.

RE: to crimp, or not to crimp
 

I don' t crimp my rifle shells but I do crimp my 44mag with a Lee Precisions crimp. Works great

RE: to crimp, or not to crimp
 

That' s real interesting. I assume that a " factory crimp " die would have to be made for each individual cartridge?

RE: to crimp, or not to crimp
 

Yup, its a collet crip die, you need a different die for each cartridge.

RE: to crimp, or not to crimp
 

Thanks Briman. I' m gonna get one and try it.

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RE: to crimp, or not to crimp
 

I wonder why target shooters DON' T crimp.

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RE: to crimp, or not to crimp
 

Target shooters demand the most accuracy that they can get.Having the most uniform pressure aids accuracy so if crimping actually did make the pressures more uniform target shooters would crimp.To quote from the second edition of sierra bullets reloading manual page 35-" Crimping generally reduces the accuracy of your loads because it adds another variable to the reloading process" . The factories crimp ammo to prevent bullets from moving in the case due to extremely rough handling which only happens in tubular magazines or when when people abuse their ammo.Also the factories use cannelured bullets almost exclusively.Even some of the bullets that have no cannelures when sold as components have cannelures in factory loads.