223-crimp or no crimp?

[Axis II]

I was told awhile back I don't have to crimp for 223 in a bolt gun but I got a lot of bullets with cannelure and began researching can I not crimp them then see a lot of guys saying crimp everything for accuracy and uniformity with bullets and pressure.

most said use a FCD or taper crimp. I'm pretty sure my RCBS dies had a roll crimp.

any thoughts?

 

[ants]

No crimp on 223 for my bolt guns. Ignore cannelure if not required.

Consistent prep, consistent loading, premium components, and clean bore make a HUGE difference. Work on those first.
Once you get tight little groups every time from the above, then explore crimp to see if it helps. Maybe. Maybe not.
But until you get everything else tidy, you won't be able to detect any affect from crimp either way, good or bad.

The vast majority of us don't crimp for a bolt gun, just make sure case necks are consistent.

 

[JimKirk]

No crimp for bolt guns .... no crimp for AR either ...

 

[cfullgraf]

Yup, me too.

I do not my 223 Remington rounds regardless if they are used in a bolt rifle or AR-15s.

 

[entropy]

I don't crimp either way. I load for my Axis and my son's AR.

 

[Bart B.]

Sierra Bullets proved back in the 1950's that crimping case mouths into bullet jackets deforms them. Those bullets don't shoot as accurate as uncrimped ones.

The arsenals loading 30-06 match ammo also learned that if they quit canneluring their match bullet and crimping case mouths into them, better accuracy was at hand.

Sierra gave into demands for their 77-gr. 22 caliber match bullet to have a knurled in cannelure so folks believing a crimp could easily shoot more accurate in AR rifles. Didn't matter to them that the best scores shot with AR's in matches did so with no crimped in bullets and commercial match .223 ammo didn't have crimped in bullets. But they test those bullets for accuracy without crimping them; better accuracy is hand. But it's not as good as the same bullet without the cannelure rolled in; proof that along unbalanced bullets enough to make them less accurate - even without crimping.

I believe that if one gets best accuracy with crimped in bullets, they're not doing all the right stuff with their reloading tools and their use. Crimping is a band aid to help reloads less than 35 caliber wounded in some way; not as good as healthy reloads with out the crimps. All those guys saying crimp everything for accuracy and uniformity with bullets and pressure, in my opinion, make wounded reloads. Talk crimping at a benchrest match and the worst performers there will laugh at you.

 

[Rule3]

Just a question, is Federal Premium Gold Medal Match ammo crimped?

 

[Comrade Mike]

Don't even bother crimping for a bolt gun.


Sent from my iPhone using Tapatalk

 

[ants]

Just a question, is Federal Premium Gold Medal Match ammo crimped?

None of my ever was. But I only bought two boxes of 308, one box of 30-06 and one box of 300 Win Mag in my life.
I load my own, so I very seldom buy or shoot factory ammo.
And I don't crimp any of it.

 

[SARuger]

Hmm. I load for the following bolt guns; .223, .243, 30-30 and 30-06. I lightly crimp all of them. No accuracy issues using a OAL that fits my mags.

I'm new to reloading, so still learning.

If I stop crimping at all do you think I can gain more accuracy? Will the recoil not cause the bullet to jump?

EDIT: After reading the next post, I didn't add that I am using the LEE FCD

 

[FROGO207]

To crimp or not to crimp, that is the question.

IF you do crimp you have to make all the brass the same length to get uniform crimp. Or if you use the FCD to avoid this you need to add that as an extra step. It turns out being lazy got me better results on target! Well I tried it both ways on several different calibers. Lots and lots on 223/5.56 and 308/7.62X51. Ultimately I found that with good bullets and hand weighed charges at 100-300 YDS that not crimping the ammo did indeed produce more accuracy. But whatever we say here I think that you should try it for your self anyway. Some here do have results that crimping does help and who am I to dispute them. I will wager that most shooters just loading up with a powder measure, random range brass, and say Cor Loct bullets could not measure the difference at 100 YDS due to the variables in the components anyway. Meanwhile I will continue to be lazy.

 

[ColoradoShooter77]

I do a light crimp on my AR-15 loads, I've got the FCD set up for a light squeeze, lol.

 

[farmerboy78]

Sierra started putting a cannelure on the 77gr smk at the begging of black hills ammo for use in the military ammo. The cannelure let the bullet fracture at a lower velocity than the non-cannelure bullets. Which equates to more lethality at longer distance.

 

[farmerboy78]

Sierra started putting cannelures on the 77gr .224 smk to make them fragment at lower velocities, equalling more lethality at extended ranges. Mainly for military contracts. They did this at the request from black hills ammo.

 

[mdi]

Ah, yes! The old "To crimp or not to crimp, that is the question". I have been on forums for several years and see this question often (no offense to the OP). If I had to rely on forum expertise, I would still be confused. For every "I crimp everything" reply, there seems to be one that says "I have no need, so I never crimp"....

So, I tested myself. I made up a bunch or .223 rounds and some crimped, some not. Compared accuracy. I made up a bunch of rounds for my Garand, some roll crimped, some FCD crimped, some no crimp. Compared bullets for "set back" and accuracy.

I paid very little attention to "I was told", and "they said" and found out for myself. My results were much more satisfying than a forum response...

 

[Rule3]

Ah, yes! The old "To crimp or not to crimp, that is the question". I have been on forums for several years and see this question often (no offense to the OP). If I had to rely on forum expertise, I would still be confused. For every "I crimp everything" reply, there seems to be one that says "I have no need, so I never crimp"....

So, I tested myself. I made up a bunch or .223 rounds and some crimped, some not. Compared accuracy. I made up a bunch of rounds for my Garand, some roll crimped, some FCD crimped, some no crimp. Compared bullets for "set back" and accuracy.

I paid very little attention to "I was told", and "they said" and found out for myself. My results were much more satisfying than a forum response...

OMG! Crimp, no crimp and Lee FCD all in one thread/post?? This thread is going to be doomed!

You did not post you actually findings? Suspense is building!

 

[steve4102]

So, I tested myself. I made up a bunch or .223 rounds and some crimped, some not. Compared accuracy. I made up a bunch of rounds for my Garand, some roll crimped, some FCD crimped, some no crimp. Compared bullets for "set back" and accuracy.

I paid very little attention to "I was told", and "they said" and found out for myself. My results were much more satisfying than a forum response...

Excellent Reply, Thanks.

Speaking of old threads and worn out topics, if ya dig back into these old threads you will pretty much find the same thing.

Those that claim Crimping with the Lee factory Crimp die is evil and will destroy accuracy have actually never tried one or even own one, and those that claim otherwise have actually experimented with it.

Thanks for posting, you make good sense in a controversial topic.

BTW, can to share your accuracy test results.

Here is an accuracy test using bolt action and the Lee Factory Crimp die.

http://www.accuratereloading.com/crimping.html

 

[steve4102]

You did not post you actually findings? Suspense is building

Yes, I would like to see his test results as well.

How about you, got any Crimp vs no-Crimp test results to share?

 

[stoky]

Sierra started putting a cannelure on the 77gr smk at the begging of black hills ammo for use in the military ammo. The cannelure let the bullet fracture at a lower velocity than the non-cannelure bullets. Which equates to more lethality at longer distance.

More nettlesome wounds at longer distance?
The only thing the 5.56x45 has going for it is velocity. That's pretty much given up with 77gr bullets and long ranges.
The primary purpose of 77gr bullets is to make small(er) groups of holes in paper at extended ranges.
IM(H)O:
roll crimp............NO
taper crimp...........maybe
I do neither. Neck tension can be an accuracy factor, but it isn't really something you can fix by crimping.

 

[Rule3]

Excellent Reply, Thanks.

Speaking of old threads and worn out topics, if ya dig back into these old threads you will pretty much find the same thing.

Those that claim Crimping with the Lee factory Crimp die is evil and will destroy accuracy have actually never tried one or even own one, and those that claim otherwise have actually experimented with it.

Thanks for posting, you make good sense in a controversial topic.

BTW, can to share your accuracy test results.

Here is an accuracy test using bolt action and the Lee Factory Crimp die.

http://www.accuratereloading.com/crimping.html

To me, the results of that test are to close to be statistically valid or much proof of either crimp or no crimp.

Perhaps if he used three rifles of each caliber to allow for the variance in barrels,

What is a "reasonably heavy crimp"?? How where the rifles supported? In a locked rest, sand bag, car door? Do we guess at the distance?

 

[Bart B.]

The actual difference between crimp and no crimp in 22 and 24 caliber rifles is about 1/10th to 2/10th MOA through 200 yards. Benchrest folks easily see that difference when their worst days have 10-shot groups about 4/10ths MOA at 200.

If your stuff won't shoot inside 1/3 MOA at 100 yards for several 10-shot test groups, you probably will not see how much accuracy loss crimping makes. I don't know of anyone who crimps shoots their stuff that well at 100 yards.

 

[steve4102]

To me, the results of that test are to close to be statistically valid or much proof of either crimp or no crimp.

Perhaps if he used three rifles of each caliber to allow for the variance in barrels,

What is a "reasonably heavy crimp"?? How where the rifles supported? In a locked rest, sand bag, car door? Do we guess at the distance?

Well at least they did a test and came up with some results.

You?

You have test results to share, or no?

 

[mdi]

I won't share my results, for a couple reasons; one, I believe in the "Give a man a fish..." thinking and two, I'm sure I would have to defend my statements/results to those that will certainly disagree. So friends, figger it out for your guns, your ammo...

Hint; Once, I forgot to crimp some Garand ammo and there were no setbacks nor gain/loss of accuracy...

 

[cfullgraf]

The actual difference between crimp and no crimp in 22 and 24 caliber rifles is about 1/10th to 2/10th MOA through 200 yards. Benchrest folks easily see that difference when their worst days have 10-shot groups about 4/10ths MOA at 200.

If your stuff won't shoot inside 1/3 MOA at 100 yards for several 10-shot test groups, you probably will not see how much accuracy loss crimping makes. I don't know of anyone who crimps shoots their stuff that well at 100 yards.

I'm in the school that you do what the top dogs are doing so if the Bench Rest shooters do not crimp, that's good enough for me.

Second, I find to get consistent crimps, which, for me, translates to consistent performance, requires alot more case preparation that I care to do. Primarily, case length variation needs to be minimized so that the crimping is consistent from one case to another. Maybe, my thinking is false as case length variation may have similar effects with un-crimped rounds as neck tension would vary a little with variation in neck length.

Third, I switched from crimped to un-crimped ammunition while I was shooting Service Rifle. I found no loss in score after the switch, maybe a slight improvement but its not a scientific study and the score differences may be statistically insignificant. As Bart said, the difference is small and maybe I would not see any change anyway. But, the time savings loading my match ammunition was worth the change.

With no ill effects of shooting un-crimped ammunition in my match rifle, I made the switch in all my rifles including AR-15s, M1s, an M1A and bolt rifles. 30 Carbine is the only rifle round I crimp and not because it improves accuracy.

Finally, never underestimate the psychological factor, if I feel better about my reloads, I will shoot better.

As some folks have said, each individual needs to determine what works best for him and his firearms.

 

[ewlyon]

I prefer to crimp any ammo that is going to be used for hunting or carry loads, or is going to be moved around a lot before it gets shot. The accuracy decrease if there is one is not enough to matter to me. But for target ammo in a bolt action I wouldn't bother unless the ammo is going to get rough treatment before shooting. If you do decide to crimp just remember that just because a bullet has a cannelure doesn't mean it should be seated to the cannelure.