To crimp or not to crimp

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prairiefire

Member
Just started reloading 223 and 6.8. Seems that there are folks on both side of the fence in regards to crimping. Most of the sources I have read say not to crimp rifle rounds, but the debate seems to heat up when AR rounds are being reloaded. What's the consensus of you veteran reloaders? Crimp or not crimp the 223 and 6.8 for AR use?
 
I shoot a lot of 223rem from a bolt gun and don't crimp but I've had necks loosen up after too many reloading's so i toss them after 4-5 reloading's. From what i have always been told was crimp is needed for AR due to bullet setback from the recoil or bolt slamming around. Someone else can help with that one. If you due decide to crimp your bullets have to have a cannelure.
 
you'd need to either use bullets with a cannelure or use a Lee factory crimp die. No cannelure required for those.

I don't crimp for my AR's.
 
I don't crimp my AR loadings in things under 450. Standard dies have imparted enough neck tension to hold them and i also use bushing dies. I only run about 0.003 tension and have good result. Standard dies often add about 0.005- 0.006 so they are more secure but I want to be able to vary the tension somewhat and they don't let me do that.

Greg
 
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A light taper crimp around the case mouth, from a Redding taper crimp die, is what I use for my auto-loading rifles; probably not necessary, but that's just my own preference.
 
i use a lee factory crimp die on just about everything i load. i've found that it hasnt affected my accuracy potential, or if it has - not enough that i can see it based on my shooting ability.

i'm just using a very light crimp, usually about 1/4 turn from contact on a Lee Factory crimp die at most.

on my 450 bushmaster i do crimp to a very specific 0.475 at the case mouth to help minimize bullet movement due to the weight of the projectiles.


the only way to know if crimping will help, hurt, or be a neutral effect for you will be to test it. Just like anything else - start light. You CAN over crimp - even with a Lee FCD! too much crimp = bad news as you can cause a pressure spike so like every other change you make when reloading test in small incriments!
 
Loaded lots of years for M1 Garand, then AR's and never crimped....until.....had a round come apart and fill the lower receiver full of powder on chambering. I am sure this was caused by the fact that I often load and unload same round during the course of predator hunting and had been just pushed the unchambered round back into magazine. Solution, I now crimp my .223's using Lee collet crimp die. Only other rounds I crimp are .375 h&h and up or for tubular magazines.

Regards,
hm
 
I usually do my load development with no crimp. After I have established a good load or two I then use a Lee Factory Crimp Die and impart various levels of crimp and retest for accuracy. If accuracy is increased I crimp at that level if it decreases I do not crimp. If there is no change in accuracy I will usually crimp just as a safe guard against bullet pull or set back. All of the above for gas guns only. I never crimp for bolt guns. In .223 especially I have noticed that accuracy can be increased in most but not all loads using the Lee Factory Crimp die to some extent. I have not noticed this too much in larger calibers. Bottom line is I try to let the gun/load tell me what it wants. Hope this makes sense!
 
I do not crimp. I have shot just over 2,000 rounds of 55grn FMJ through my AR's and have never had one set back or come apart. I do not crimp for 22-250, 243 or 25-06 either. I have not had a problem yet, not saying it cannot happen.......I just have not seen it yet.
 
one side note - if you have to use an expander on your brass for seating reasons - that is the one time you will *HAVE* to crimp to remove the bell you put on with the expander. Most FMJ loads dont require it, but any cast or just plated rounds will (most common in pistol applications, but have some rifle applications too).

again when doing so, you only need to use your FCD to remove the flare, and if you so choose to apply a mild crimp too.

Be extra careful when crimping plated/coated rounds, its easy to cut thru the coating/plating.
 
For the AR, crimping is not an issue. The 5.56/.223 just doesn't produce enough recoil to worry about it. Maybe when you load for an A10 in the bigger cals, but I still doubt it. Use to load 30-06 for my M1 Garand and never crimped. Just one less thing to worry about.
 
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