To crimp for AR or not.

[4xforfun]

Just like the title says......going to jump into the AR world. Do any of you guys crimp your loads? Is there two different "sweet spots" for crimped vs non crimped loads? Does crimping affect your accuracy....as in......"non crimped load shoots good, but after crimping not so much"?

Thanks,
Tod

 

[DiRTY DOG]

Crimping solves a specific problem. If you don't have that problem...

 

[Hoser]

For accuracy ammo? Nope. Dont do it. No way.

 

[acloco]

I use a LIGHT taper crimp for semi auto AR feeding.

 

[jelenko]

Never crimped. Am running 3 thousandths neck tension.

 

[Walt Krafft]

I have shot 30-40,000 rounds through AR rifles without crimping. Dont do it.

 

[Downhill]

Used the AR for Across the Course since 1992. Never crimped. No issues.

 

[dellet]

Might depend on cartridge and bullet weight, combined with gas system and how it’s tuned.

Any more when “getting into AR’s” could mean anything from a 6-30” barrel and bullets from 20-250 grains, a generic answer will have some exceptions.

The heavier the bullet and the more over gassed, higher bolt speed, the more likely a bullet is to slip forward when chambering. It’s something to be aware of, and if you shoot a lot of different bullet weights, a crimp might be worth considering in certain circumstances.

 

[Hoot]

I'd crimp any straight-walled AR calibers. Since they headspace off the mouth, you need the extra hold-back force to keep the bullet from pulling during the cycling process. Think inertial puller. I've played with the 450 Bushmaster a lot since 2010. They for example, need a crimp.

Hoot

 

[Pawnee Bill]

Neck crimping is waaay overrated and mostly unnecessary.

 

[Doug Casner]

I crimp mine just a little. Using a 550 dillon.. They feed better and Ive shot inch groups at 100. Good enough for me. Doug

 

[762plinker]

so while most did not mention it, in target or competition shooting...no..about 3 thou neck tension works well while .002 works for mos but not all.
for blasting ammo with 55 and 62 common low dollar bullets trim to length and crimp.
(notice no one said nothing about trim to length,)

 

[markm87]

I ran a bunch of crimp tests years ago. (My OTM/Target loads get shot in bolt gun and AR) Since I DO NOT anneal 5.56 neck (due to volume),I use the LEE Factory Crimp Die to somewhat unify the neck tension on mixed brass.

To my surprise, the first time I tested NON-crimped against Lee FCD crimped 77 gr OTMs, the Non-crimped group size was double that of the Crimped. At that time, it appeared that the crimp (as the ONLY variable in the test) improved consistency.

I repeated this test a few months back, and also included the Taper crimp as a 3rd variable. At that time, I could see no significant difference in accuracy in any of the 3 variables.

So at this point I still run a Light Factory crimp on ALL my 5.56 ammo, including single feed 88 gr ELDMs for bolt gun. The crimp most certainly doesn't do any harm in my process.

I just bought 2 more Lee FCD dies in 5.56 because they do wear out and stick after 20k or so crimps.

 

[markm87]

For anyone to post ABOLUTE Yay or Nay on crimping is absurd. It's all about the complete process. You can certainly build excellent ammo without a crimp if you refine your process. And you can also build outstanding ammo with a crimp.

I know guys on other forums who have a process almost opposite of mine, and we both get outstanding .223 target ammo.

 

[4xforfun]

K...a little more info.....223 rem... 80VLD, 80.5, 85.5, 80 ELD, ETC.... in that 2400 - 2600 FPS range. I have quite a range of powders.....Benchmark, Varget, H335, H322, RL15/15.5/16/17 Not looking for speed. Looking to buck the wind and accuracy. I may even single feed them to negate the whole "fit in the mag" thing. 1-7 or 1-8 twist. 20+ inches

 

[karrarararararar]

K...a little more info.....223 rem... 80VLD, 80.5, 85.5, 80 ELD, ETC.... in that 2400 - 2600 FPS range. I have quite a range of powders.....Benchmark, Varget, H335, H322, RL15/15.5/16/17 Not looking for speed. Looking to buck the wind and accuracy. I may even single feed them to negate the whole "fit in the mag" thing. 1-7 or 1-8 twist. 20+ inches

None of the bullets you listed are for mag length ammo. 2700-2800 fps with excellent accuracy is easily achievable in a 20+ inch barrel. Less than that, you'll get the same performance with mag length 77's at a faster velocity.

Of the powders you listed, varget and RL15.5 are the ones I'd look at. 24gr of either will shoot well.

On the topic of crimp; while it is not necessary, i did experience lower SD's when I shot Tac with a light crimp vs uncrimped.

 

[dcali]

It’s not necessary. You will probably find that the bullet moves when you chamber it, but only a little and it’s pretty consistent in my experience. Crimps are overkill. Not worth the extra step.

 

[Rsadams]

Yes I apply a light crimp....

 

[dannyjbiggs]

Why bother, unless you're thinking of sending some handloads to the Your-crane! In the past, I've "roll" crimped on .223/.308 bullets bearing a cannelure; but I've never felt the need to "taper" crimp other styles of non-cannelure bullets. Let the military deal with it for their purposes, you really don't need to.

 

[6fatrat]

I don't