223 Rem to Crimp or Not


August 15, 2010, 06:01 PM
I've been reloading pistol ammo for years. The 223 Rem is my first rifle cartridge. I've got the dies and read all my old reloading books. I've reloaded a few and things are going along well.

My question: Is a taper crimp die used for 223 Rem.

Thanks, Fourbits.

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highlander 5
August 15, 2010, 06:10 PM
I use a taper crimp die myself,but some taper crimp some roll crimp some don't crimp.
What type of rifle are you using them in? I have both semi auto and bolt rifles and use a light crimp .

August 15, 2010, 06:20 PM
Normally you don't have to crimp 223 rounds. If it makes you feel better however, give your cases a "kiss" of crimp with your seating die. Assuming that all your cases are of the same length.

August 15, 2010, 07:23 PM
If you are using them in an AR type weapon. You may want to put a little bit of a crimp on it. It keeps the bullet in place during the slightly violent chambering process. If you are using them in a bolt action or lever action, then a crimp really isn't neccessary.

August 15, 2010, 08:49 PM
I've wondered about this myself. I've done .223 for a while, but only recently got an AR-15 (previous was all bolt action; no crimp).

I'm full length sizing with Lee, and I tried to take apart some of my (uncrimped) rounds using a kinetic (hammer) puller on the carpet to the cement..... wow! Pound, pound, pound pound POUND! to get them to come out. I was IMpressed!

I don't have much experience, maybe only 100 rounds so far, but my uncrimped rounds seem to be doing fine.

The chambering movement should move the bullet farther OUT of the round....but because of the magazine limitation, I'm already seating these at SAAMI spec--which is MUCH DEEPER than I'm used to. For the bolt action, I chose .020 off the lands, far farther out than I'm seating these! I shoot fairly mild loads (for target practice) and if the bullet WERE to go out to the lands, it probably will still be well withinn any pressure limit! I've shot hotter loads with bullets into the lands before with a bolt, no problem.

So I'm not real sure why I would need to crimp these? Now, I get a LOT of usage out of one case, since I use fairly low pressure charges, and as the neck work-hardens, then the pressure on the bullet may lesson, and they may move a bit more and change my theory.

August 15, 2010, 08:55 PM
You can taper crimp, roll crimp, or not crimp at all if neck tension is sufficient. (You need good neck tension regardless)

To roll crimp you need a good cannelure (not just marks), and the brass needs to be trimmed for consistent length.

Taper crimping is much more forgiving of case length, but I recommend trimming anyway for consistency.

August 15, 2010, 08:57 PM
If you search, there are threads galore on this topic. It's a religious debate - some do, some don't. I never have with my 2 ARs and have had no ammo related problems at all. With adequate neck tension there's just no need.

If it makes one feel better, crimp away!

Shawn Dodson
August 15, 2010, 08:57 PM
Apply a crimp to minimize the risk of bullet setback when fired from autoloading rifles. Bullet setback can occur when the nose of the bullet collides with, and rides against the feed ramp as the cartridge is chambered from the magazine.

August 15, 2010, 10:19 PM
I've reloaded a couple of thousand .223 rounds, most have been mild charges, and I've done both crimped and uncrimped variations, with no appreciable difference either way. That is, I've seen no malfunctions, and no measurable change in accuracy. That having been said, you should only consider crimping on bullets that have a cannelure. Otherwise, you're forcing the brass into the bullet, which can't be good for aerodynamics.

August 15, 2010, 11:01 PM
I use a Lee Factory Crimp die. After I started using it, I'm getting better consistency out of my AR and the amount of crimp applied is not dependent on the case length. I apply a very light crimp.

gun guy
August 15, 2010, 11:20 PM
Let's say you have a 30 rd mag in your ar. Each time you fire, the remaining rounds in the mag are battered back an forth. Load a blitz or spire point bullet in the number 30 spot. Pull it out an look at it after you fired 28 rounds. I rest my case. If you fail to crimp your ammo, plan on cleaning out a magazine full of gunpowder. The internal battering is even worse in a 308. If you wish to load bullets that are not cut with cannelures, there is a hand crank tool that will cut the groove into sporting bullets you wish to use, so you can crimp them too. A mild crimp is usually adaquate unless your working on the heavy end of the load. Have a great day.

August 15, 2010, 11:20 PM
It probably is not necessary to crimp even in semi autos. However, I do it just for good measure.

gun guy
August 15, 2010, 11:39 PM
If you decide not to crimp the rounds in your AR, keep a couple spare gas key allen bolts handy. Bullet set back causes over pressure problems at the gas key, the common failure is front bolt fracture, causing a gas leak, and the weapon to short stroke. If you don't mind drilling and using an easy out on your bolt carrier to replace a broken bolt, dont bother to crimp, heck, its not my gun.

August 16, 2010, 12:18 AM
Half of the bullets I shoot in my AR's don't have cannelures so I don't crimp them. The other half don't get crimped because I don't want to mess with my seating die other than setting the seating depth.

Tim the student
August 16, 2010, 02:44 AM
In my AR, I don't. There just doesn't seem to be a need to, and I'm pleased with my accuracy.

August 16, 2010, 06:48 AM
Bullet set back causes over pressure problems at the gas key
The greatest likelihood however, if there is bullet movement at all, is that it will creep forward in the case. The inertia imparted by the bolt slamming the round into the chamber tends to cause the bullet to creep out - the opposite of setback - and will reduce pressure.

See the linked Sierra article, about 80% of the way down under Neck Tension.


August 16, 2010, 12:13 PM
Thanks to everybody! The rounds will be used in an AR15. I think I'll give them a mild taper crimp.

August 16, 2010, 08:44 PM
Like Loadedround said,I like a gentle kiss on mine!

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