Crimping .223 for AR's


January 31, 2008, 11:29 PM
Hmm.. I see Yes crimp, No crimp. So what to do? I will probably have about 2,000 rounds with crimp cannelures coming in so i can crimp if I want to but??

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January 31, 2008, 11:42 PM
We shoot a lot of 223 in competition, both cannalure and smooth. You don't need to crimp.

Grandpa Shooter
February 1, 2008, 12:58 AM
I posted that question on three forums and got some conflicting answers but generally the consensus from people who know a whole lot more about .223 than I ever will say, NO, it is not necesssary if you are properly resizing the brass. If you can press the bullet into the neck of the case with minimal pressure, either the bullet diameter is wrong, or you have not adjusted your die properly.

I made sure to follow their advise and have built some good looking rounds to go out and try when the ground dries up some.

Plain Old Bill
February 1, 2008, 01:16 AM
If you're shooting a semi-auto, crimping is the safer thing to do. Didn't think much of the idea myself at first but have seen instances where the bullet has gotten knocked back into the case completely during a misfeed. I crimp all my semi-auto stuff.
Your mileage may vary.

February 1, 2008, 01:18 AM
I don't crimp my .223 nor my 22-250 and personally I would never crimp any other 22 caliber bullet because the bullet for the following reasons:

The bullet doesn't have enough mass allow it to move upon recoil in a properly resized case; If you have doubts then try to pull a bullet with a kinetic puller.
Crimping the bullet works the neck and will over time cause the neck to split.
Crimping can affect accuracy

Now with that said if you're one of those folks that don't take care of their ammo and just toss it into a 5 gal bucket or ammo can then you might want to consider crimping. Tossing and carrying bullets in a bulk container around will not only damage their points, which will affect accuracy, but can seat the bullet deeper into the case and can cause over pressure situation.

February 1, 2008, 10:33 AM
I didn't crimp my first 1k and they all worked fine but for safety reasons I crimp everything else. Just preventing a KB. I had a KB due to setback in my 9mm ar(one I made) nothing broke, just got dirty. I now crimp those rounds.


February 1, 2008, 02:18 PM
I do for AR .223 rounds.

To each his own I guess.

For non semi auto loading rifles I don't crimp at all.

February 1, 2008, 02:40 PM
I started crimping for AR's and Mini-14's some years ago with FMJ bullets with a cannulure.

A couple of years ago, I was loading Nosler B-T varmint bullets for an AR and decided to run some tests to see what effect it had on accuracy.
(Everyone knows you can't crimp a non-cannulure bullet without ruining it, right?)

Too my surprise, it certainly didn't ruin the Nosler B-T bullets!

February 1, 2008, 02:47 PM
As long as there is sufficent neck tension, then I have found no difference between crimped and not crimped. I have tried to get the rounds to set back in my AR with no luck. I have seen no change in accuracy.

February 1, 2008, 02:52 PM
I have found the same and also reverse. I would try it with and with out to see if your accuracy improves or not. This would be the best all though I do crimp for anything holding more than 5-10 rounds I see it as a kinetic bullet puller. Do this take your bullet puller and tap it on the ground 30 times (not hard) this is what the bullets are doing in the magazine.

February 1, 2008, 02:58 PM
If I were into paper punching, I would probably follow the no-crimp crowd. As I am not, I use the Lee FCD in .223 for the AR, and it works well. For varmint loads in my 700V bolt gun, I obviously abjure the crimp.

February 1, 2008, 03:06 PM
I would try it with and with out to see if your accuracy improves or not.I did.
The target in the picture I posted shows #1, 2 & 4 uncrimped.
#3 is crimped.

BTW: Feed ramp impact is what you need to worry about in an auto rifle. Recoil in an AR mag is not the culprit.

Recoil in a .458 WinMag box magazine, or in a 30-30 tube mag is also worth your consideration.

February 1, 2008, 04:59 PM
I don't know what AR you will be firing from, but I absolutely have to crimp for my M4. Every time I pull the trigger on this Colt it has significant recoil and muzzle blast. I had several hundred rounds that were uncrimped when I first bought the gun. After the third shot I started getting bullet setback.

FWIW, those same rounds fired just fine with no setback in my other AR.....of course that wasn't a carbine either.

February 1, 2008, 05:09 PM
I took 100 uncrimped rounds to the range at work. Fired them on semi and full. I would stop every few rounds and pull one out of the mag and measure it. I did not find any setback. Maybe just the way I set up my dies, I don't know. I have been crimping for all my other rifles and pistols, but thought it would be a nice time to experiment. I also took an old USGI mag and loaded it with some rounds and basically beat it to death (trying to imitate the kinetic bullet puller), still nothing. The mag is dead though. I would like to know what I am doing different then everyone else that has setback. I am using the RCBS xdies. Is it my setup?

February 1, 2008, 05:20 PM
I would try it with and with out to see if your accuracy improves or not.

I did.
The target in the picture I posted shows #1, 2 & 4 uncrimped.
#3 is crimped.
this is for your gun but as for his it might be just the reverse might not. That's all I was trying to say try both ways in his gun and see which one does better

February 1, 2008, 07:39 PM
I'll be using it in a 24" bushmaster upper. the recoil is very mild, I'm planning on doing base loads with h335 to start out with so I will just have to try and see..

forgot to say that they will be 62gr greentips.

February 1, 2008, 09:16 PM
I've probably run about 1000 62 g green tips through three ARs (Colt/BM/Colt Upper on a Mega Receiver) and a Galil. No crimp, no problems. Using 25g of IMR 4895.

February 1, 2008, 09:48 PM
To me it's like weighing every 5th or 10th charge when throwing loads... Just takes a few seconds and certainly won't hurt anything.

February 1, 2008, 09:55 PM
Just a guess, but those with set-back issues may have neck tension issues. I'm with the group that has shot zillions of .223, .308 and .30-'06 through auto-loaders with no problems, except for one Century FAL that had feeding ramp issues.


February 1, 2008, 10:53 PM
I crimp for everything that isn't a bolt action or a single shot.

February 1, 2008, 11:08 PM
I crimp for the AR's and Garands.

February 2, 2008, 01:31 AM
I've never crimped for 223, and I've shot thousands of rounds (probably well over 10k) out of my 2 AR's. I use 55gr FMJ and 50gr Nosler's.

That said, I'm planning to run off a batch of 77gr SMK's (scored on a box of 500 thats got a cannelure) for SHTF duty, and those WILL get crimped.

February 2, 2008, 09:12 AM
Well I don't have an AR I have two SKS rifles a 300 Sav. and a Russian M44 and a 30-30. I use the Lee FCD on all these Rds. it make no difference whether I use cannalure or non-cannalure bullets the crimped Rds. shoot more accurately than the non crimped.

dagger dog
February 2, 2008, 09:49 AM
thats the big word, if you,were betting your life, that the next round in the mag will feed and fire , would you crimp?

do i crimp? no not on sporting or hunting ammo in non-selfloaders. but when loaded for dangerous game two or four legged, something comes to mind about large furry animals defecating in the forest!

have fun always dagger dog

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