To crimp or not to crimp .223

[sfl_gunner]

I have been loading .223 for a few years now. Most of my loads are for High Power competition shooting using single loading. Typically heavier bullets like 77 to 80 grain. I have never crimped but now I’m looking at loading some plinking ammo that may stay loaded for a couple of months at a time before shooting. It seems like a lot of people crimp and recommend crimping. I’ve never done it and never had any issues. So to crimp or not to crimp? That is the question.

 

[Charlie98]

I taper crimp my blasting ammo, I think it's a pretty good idea considering the shorter 55grn bullet.... and my bullets have a cannelure anyway. Same same with the blasting ammo for my M1a (7.62mm) but not match bullets.

 

[Blue68f100]

If neck tension is right NO Crimp is needed. I do not crimp any of my AR ammo. I do use a 0.003" neck tension, this is enough to prevent bullet set back. Load up a dummy round and see how you gun feeds, checking OAL before and after. This will tell you if your good to go.

 

[Bartojc]

I have been loading .223 for a few years now. Most of my loads are for High Power competition shooting using single loading. Typically heavier bullets like 77 to 80 grain. I have never crimped but now I’m looking at loading some plinking ammo that may stay loaded for a couple of months at a time before shooting. It seems like a lot of people crimp and recommend crimping. I’ve never done it and never had any issues. So to crimp or not to crimp? That is the question.

Bolt rifle or AR ? I crimp my .223 that I shoot in my AR. For bolt rifles I do not. If neck tension is correct you should not need to crimp, but for an AR (semi-auto) I do it as an added safety measure.

-Jeff

 

[sfl_gunner]

It’s for an AR.

On the RCBS 2 Die Set. Their website states that the seater die has a roll crimp. Is that good enough of a crimp?

 

[Charlie98]

It’s for an AR.

On the RCBS 2 Die Set. Their website states that the seater die has a roll crimp. Is that good enough of a crimp?

Be careful with a roll crimp... if you try to put too much crimp in, you can either buckle the shoulder (particularly in thin cases like the .30-30...) or you will actually take some of the neck tension out by reverse belling the case mouth. This is one of the reasons I use a taper crimp... case trim length isn't as critical, and it's more of a gradual crimp... not as hard on the case mouth as a roll crimp, and won't deform the bullet (when used on a bullet without a cannelure.) Blue is right, however... if neck tension is proper, you don't really need a crimp at all.

 

[Laphroaig]

A roll crimp is meant to be crimped into a cannelure. It will damage the jackets of your match bullets.

Its not necessary.

 

[MEHavey]

Barring truly exceptional conditions/problems (which you should correct anyway....)
No crimp on gas gun cartridges

 

[taliv]

for an AR

match ammo / bullets - do not crimp
blasting ammo / bullets with cannelure - definitely crimp
blasting ammo / bullets without cannelure - eh taper maybe but not roll

 

[Chuck R.]

I'm in the no-crimp corner.

The only rifle ammo I've ever crimped was shot in a rifle with a tube magazine. Probably 99.9% of the time neck tension is enough, especially with factory FL dies.

 

[AJC1]

I'm trying to understand what crimp has to do with long term storage. If storage is the goal then sealing might be more what your after. If damp conditions are present then this sealant will prevent problems. If were talking about a few weeks to a few months no problem. Crimp can help with setback issues if you intend to address that but neck tension can be increased to deal with it as well.

 

[taliv]

But most dies people use for blasting ammo have no way to control neck tension.

precision ammo and bushing dies you can vary the bushing

 

[cfullgraf]

I also do not crimp my bottleneck rifle ammunition, gas gun or bolt. This includes my Service Rifle competition ammunition back when I was competing.

I’ve gotten away from using any old pick-up brass so my cases are more uniform and I can control neck tension.

 

[ArchAngelCD]

I put a light. Romp on my .223 ammo but it's not a necessity. I'm not even sure why I do.

 

[AJC1]

But most dies people use for blasting ammo have no way to control neck tension.

precision ammo and bushing dies you can vary the bushing

You can polish or change the expander ball or use a separate expander mandrel

 

[Ruger 15151]

.003 - .004 neck tension is all you need. I don't think a crimp is ever necessary on rifle cartridges for civilian use. I think the purpose of crimping 223/5.56 rounds was to prevent bullet setback while they are bouncing around loose in a steel ammo box in the back of a Humvee in the middle of Afghanistan.

However, its pretty easy to test. Load 10 rounds into you mag and fire 9. Measure the tenth. If you have bullet setback (bullet sliding back into case), then maybe you need to just increase neck tension.

 

[.308 Norma]

I'm trying to understand what crimp has to do with long term storage.

Me too. I have some non-crimped 30-06 ammo that I loaded probably 20 years ago for my old Ruger 77. It's been sitting on a shelf every since I loaded it, and I'd bet dollars to donuts it will work just fine.
I too am in the "no crimp camp" for most bottlenecked cartridges. My 30-30 and my wife's 32 Special (both Model 94s with tubular magazines) are exceptions. I roll crimp them - into the cannalures.

 

[FROGO207]

I find my rifle ammo is more accurate if NOT crimped. I am into accuracy so no crimp unless it is for a tubular fed firearm. Those I have to crimp for safety. You should try yours both ways and make that decision after.

 

[Average Joe]

I do, you only need one bullet setback to ruin your day.

 

[brewer12345]

So, stupid question: I routinely crimp my rifle rounds because most of them are either cast bullet loads where the case has been generously flared to seat the bullet, or because they are going into a tube magazine. So if you are loading a jacketed bullet into a round destined for a semi auto rifle you flare the case, drop the powder, seat the bullet. Then you don't crimp? How do you remove the flare?

 

[.308 Norma]

So if you are loading a jacketed bullet into a round destined for a semi auto rifle you flare the case, drop the powder, seat the bullet. Then you don't crimp? How do you remove the flare?

I don't flare the cases when I'm using jacketed bullets - a little chamfer in the case mouths is all I need. Of course the only semi-auto rifle I load for is an old Model 100, 308 Winchester, so I don't know for sure whether or not you need to flare the cases when you're loading jacketed bullets for an AR or something like that. I wouldn't think so though.

 

[Bfh_auto]

But most dies people use for blasting ammo have no way to control neck tension.

precision ammo and bushing dies you can vary the bushing

I turned down the expander ball with a drill and an Emory cloth tacked to a board. I did this until I had no bullet setback.
I'm in the no crimp crowd also. My wife's 30-30 great a slight crimp and my H110 357 loads get a heavy crimp. Everything else better hold on its own.

 

[brewer12345]

I don't flare the cases when I'm using jacketed bullets - a little chamfer in the case mouths is all I need. Of course the only semi-auto rifle I load for is an old Model 100, 308 Winchester, so I don't know for sure whether or not you need to flare the cases when you're loading jacketed bullets for an AR or something like that. I wouldn't think so though.

Ah hah, therein lies the answer. Like I said, I come from the side of loading relatively fat cast bullets. If you do not flare, they are not going into the case mouth. I bought a 350 Legend upper and will be trying to load for it pretty much exclusively with jacketed bullets, so I will forgo the flaring.

 

[cfullgraf]

Note, a crimp is not a substitute for insufficient neck tension.