[Ferdinandd]

Just over a month ago I started shooting my new Spike's Tactical AR in .223. I've reloaded .223 for Contenders, bolt-actions, and Mini-14's. Is crimping recommended when reloading for an AR to prevent set-back of projectiles in cartridges in the magazine, or for other reasons? Brass tends to last longer when processed less, but I don't want to generate undesireable results if crimp is needed but not applied. Thanks in advance.

[Gunnut 45/454]

If the bullet style has a crimp grove yes! If it doesn't then just be mindful of bullet tension while seating if it doesn't feel tight then I'd through a crimp on it just to prevent set back! Unlike bolt guns and single shots you'll not see setback!

[DougW]

I find that the tension of the case mouth on the .223 is so tight that I don't crimp. I have to use a collet puller to pull bullets from .223, as a kinetic puller will not work (for me at least). I have never had a set back issue with my AR's.

[jem375]

I have yet to crimp a rifle bullet when reloading and don't intend to do so, unnecessary....

[JBnTX]

If the bullet has a cannelure grove, crimp it in that grove.

If it doesn't, I adjust my seating die to give the bullet just the ever so
slightest crimp at the COL I want.

I've chambered 5.56 and 7.62 rounds over 10 times with no setback using
this method.

Remember, just a little crimp goes a long way.

[MajorD]

I've seen some AR's choke on ammo that was uncrimped but did fine with a slight taper crimp on the case mouth. if your rifle runs fine without a crimp no need to add this step.

[ColoCG]

I load Hornady 55gr. FMJ w/cannelure and 55gr. SP w/cannelure and have never needed to crimp either for my AR.

The neck tension holds the bullet very solid. Crimping the bullets can sometimes affect your accuracy if the crimp is inconsistent, which can happen with different thickness or different lenghts of brass.

If your bullets are held tight enough why risk complications.

[bmoore]

I just started loading 223, i did some research on this. I shot 40 of my non crimped reloads out of 2 of my AR's (Palmetto state upper and DPMS upper) the other day and did not have a problem. The bullets seem very secure without needing a crimp, I tried moving a few after being loaded and they did not move at all. I am going to run some through my Smith M&P15 to make sure it likes them.

[Ahmid]

I do a slight taper crimp on my 5.556X45 cartridges. I started doing that because I was having feeding problems. Later on I found the feeding problems was caused by a dry AR15, not enough lube. I got into the habit of the slight crimp so I still do it.

[Zombie Steve]

If you decide you have to roll crimp into a cannelure, do it very lightly. Doesn't take much to buckle the brass.

FWIW, I have crimped in the past, but generally don't anymore.

[oneofthose]

I've only reloaded pistol cartriges, but here's what I do if experimenting with a new bullet or slightly hotter load:

In a revolver, load 6 rounds and fire 5, then check the COL of the 6th round to see if the recoil from the first 5 rounds was enought to move the bullet. I've never had one move, but i've only loaded 38 special, no magnums.

In an autoloader, (I've never tried this, but you could try it and post your findings here) I suppose you could load and fire a full magazine, pausing to extract the 5th, 10th and 15th round and check COL.

You could also cycle several rounds (without firing) allowing the bolt or slide to close with full force, to see if the bullet slides forward when it slams home in the chamber.

[TDC20]

I have fired literally thousands of uncrimped rounds from my RRA AR-15 in Highpower competition over the years without a single issue. This includes slow fire single loading of 80gr bullets longer than magazine length as well as many, many 10 shot rapid fire strings from the magazine. I have never had a single problem. Your AR could be different concerning feeding (I seriously doubt not crimping is the cause of feeding issues), but the only rifle cartridge I crimp is .30-30 due to loading into tubular magazines, which could cause bullet setback during recoil.

For as low recoiling as the .223 is, I don't see crimping as necessary. However, the military does, so maybe for ultimate reliability, you would consider crimping.

[Giddyupgo55]

If the bullet has a crimp grove I will use it otherwise I apply a slight taper crimp. Just my 2 cents worth.

[Ferdinandd]

Thanks for the replies all. I had overdone the crimp on 20 rounds that I loaded for testing and had 3 of them split - these cases have been loaded several times though. I'm going to start going without the crimp now that I've heard from folks with more experience with this. If I get organized I'll try to check OAL as I make my way through a magazine.

[Bret]

As others have stated, it's probably not necessary. However, I crimp the 55gr FMJ's anyway just because they have a groove. Rather than roll crimping, may I suggest using a Lee Factory Crimp Die for bottle necked rifle cartridges (not for straight walled pistol cartridges). Instead of a roll crimp, it applies a crimp that, as the name implies, looks like one that comes from the factory. It's easier to adjust correctly and is not as sensitive to case length as roll crimping.
http://leeprecision.com/xcart/Factory-Crimp-Die/

[bmoore]

Originally Posted by TDC20

I have fired literally thousands of uncrimped rounds from my RRA AR-15 in Highpower competition over the years without a single issue. This includes slow fire single loading of 80gr bullets longer than magazine length as well as many, many 10 shot rapid fire strings from the magazine. I have never had a single problem. Your AR could be different concerning feeding (I seriously doubt not crimping is the cause of feeding issues), but the only rifle cartridge I crimp is .30-30 due to loading into tubular magazines, which could cause bullet setback during recoil.

For as low recoiling as the .223 is, I don't see crimping as necessary. However, the military does, so maybe for ultimate reliability, you would consider crimping.

You shot a RRA in competition???? That would be an 8 page thread in the black rifle forum.

[PCJim]

Unnecessary.

In rifle, I load bullets both with and without a cannelure, no crimp. The case mouth has more than enough purchase to hold the bullet in place. I have tried the Lee crimp die and did not like the way it worked the case mouth.

[TDC20]

Originally Posted by Bret

As others have stated, it's probably not necessary. However, I crimp the 55gr FMJ's anyway just because they have a groove. Rather than roll crimping, may I suggest using a Lee Factory Crimp Die for bottle necked rifle cartridges (not for straight walled pistol cartridges). Instead of a roll crimp, it applies a crimp that, as the name implies, looks like one that comes from the factory. It's easier to adjust correctly and is not as sensitive to case length as roll crimping.
http://leeprecision.com/xcart/Factory-Crimp-Die/

The Lee FCD is what I use on my .30-30 loads. I've been very happy with it.

[TDC20]

Originally Posted by bmoore

You shot a RRA in competition???? That would be an 8 page thread in the black rifle forum.

Is that bad? I've never been to the black rifle forum here, so I don't know. My Rock River NMA2's shot 5 shot .75" groups right out of the box. They are reliable and have nice 2 stage triggers. I'm very happy with them. The only thing I would change about them is the barrel twist. I would rather have a 7 or 7.5" twist than the 8" that came with them. But they're nice barrels, clean up real easy, too.

I'm not sure if your post is good, bad, funny, sarcastic or what. Sorry for my ignorance.

[steve4102]

This is what Sierra has to say about it.


Neck Tension

When we stop to consider the vigorous (read, downright violent) chambering cycle a loaded round endures in a Service Rifle, it becomes pretty clear it suffers abuse that would never happen in a bolt-action. This is simply the nature of the beast. It needs to be dealt with since there is no way around it.

There are two distinctly different forces that need to be considered: those that force the bullet deeper into the case, and those that pull it out of the case. When the round is stripped from the magazine and launched up the feed ramp, any resistance encountered by the bullet risks having it set back deeper into the case. Due to the abrupt stop the cartridge makes when the shoulder slams to a halt against the chamber, inertia dictates that the bullet will continue to move forward. This is exactly the same principle a kinetic bullet puller operates on, and it works within a chamber as well. Some years ago, we decided to examine this phenomenon more closely. During tests here at Sierra’s range, we chambered a variety of factory Match ammunition in an AR-15 rifle. This ammunition was from one of the most popular brands in use today, loaded with Sierra’s 69 grain MatchKing bullet. To conduct the test, we chambered individual rounds by inserting them into the magazines and manually releasing the bolt. We then repeated the tests by loading two rounds into the magazine, chambering and firing the first, and then extracting and measuring the second round. This eliminated any potential variation caused by the difference between a bolt that had been released from an open position (first round in the magazine) and those subsequent rounds that were chambered by the normal semi-automatic operation of the rifle. Measuring the rounds before chambering and then re-measuring after they were carefully extracted resulted in an average increase of three thousandths (0.003") of forward bullet movement. Some individual rounds showed up to seven thousandths (0.007") movement. Please bear in mind that these results were with factory ammunition, normally having a higher bullet pull than handloaded ammunition.

To counteract this tendency, the semi-auto shooter is left with basically two options: applying a crimp or increasing neck tension.

Article
http://www.exteriorballistics.com/re...sgunreload.cfm


I crimp all of my auto-loader ammo with the Lee Factory Crimp die. It works great,Keeps the bullets secure, bullet doesn't need a cannelure, case length is not critical and it improves accuracy.

[Zombie Steve]

Excellent post, Steve (do we have a nickname for you yet? Too many Steves ).

That's been my experience exactly. Mine tend to be about .003" - .005" longer after chambering. As long as you know it, it's no big deal. Even with a 69 grain Matchking loaded to max OAL it doesn't hit the lands in any of my AR's. Keep in mind they won't fit in the mag if you chamber and try to reuse them. I just load them .005" off max and don't sweat it.

[GIockGuy24]

If the bullets have a cannelure you can roll crimp but lack of a crimp is usually alright with proper neck tension. Bullets that do not have a cannelure should not be roll crimped at all. Then there is the Lee Factory Crimp Die which is a type of taper crimp. It can be used with non-cannelured bullets but it needs to be set up to not damage the bullets. Trying to roll crimp without a cannelure can cause loss of neck tension and can sometimes cause unwanted bulges.

[freakshow10mm]

I don't crimp but instead use the Redding bushing sizer die to set the correct tension.

[Bret]

Originally Posted by freakshow10mm

I don't crimp but instead use the Redding bushing sizer die to set the correct tension.

Would you please explain the concept behind how this works?

[steve4102]

Originally Posted by Zombie Steve

Steve (do we have a nickname for you yet? Too many Steves ).

.

My wife calls me "Ass Hole" if that works?