AR15 in flight tumbling rounds proof

[Whiskey3]

Third time at the range with my new AR15 build.
Shooting at Cordova Shooting Center on the 25 yard range.
After several full magazines, at the break I pulled the paper target.
See pic. Proof that at least some AR round tumble in flight.

I used a mix of ammo.
Unfortunately dont recall which ammo went to which circle. Used . . .
American Eagle 223, 55 gr.
IMI 5.56, 62 gr.
Freedom Munition 5.56, 62 gr.

Rig is a Aero Precision complete upper M4E1.
16" CMV 5.56 mid length barrel, 7:1.

So proof that it does occur.
No idea why.

[9M62]

Probably the IMI.

I've never, ever, had a problem with AE or Freedom -- but I've had tons of problems with IMI.

A complete guess though, if I'm being honest...

[ProtectThe2nd]

.223/556 tumbling is not a good thing until after impact where it's supposed to tumble...

Your 25 yard tumbling is reason for concern and should be addressed

There are various reasons that you should look into...quality or lack of correct rifling...muzzle device baffle strikes...really poor ammo quality...completely worn out barrel...totally incorrect bullet grain weight for twist...etc

I've never heard anyone deny a round can keyhole in flight...but the military wanted a round to tumble AFTER impact since by convention expanding bullets are prohibited in combat

Edit: in flight tumble results from gross instability...not by design

[randomthought]

It's called keyholing. It can happen with rounds that are not stabilized properly. Never seen that happen at 25 yards though. Bad batch of ammo possibly? 1:7 is supposed to prefer heavier bullets, but should shoot 55 no problems. I've never had issues anyways.

[Nguyen]

Never had any issues with IMI, but at the same time I haven't shot a lot of them (500~ rounds)... Try the ammo on a different upper.. if the same results then its the ammo. If not, then its your barrel.

[highpower790]

Light weight bullets and a fast twist will not show a positive result.

[Rbutler]

too fast a twist! a 7:1 will detonate most rounds!

jk I'd try to isolate which did what.

freedom has a bad rap 3 guns blown up in reddit were all using freedom reloads. and that was just last week

[Cheezle56]

too fast a twist! a 7:1 will detonate most rounds!

So much fail in that statement... only >40 grain varmit rounds.

[Cokebottle]

Light weight bullets and a fast twist will not show a positive result.

Not ideal, but they won't keyhole.

You'll keyhole a 62gr out of an old 1:12 or slower.
1:7 is overkill for 55gr, but it'll basically overstabilize it.

[Cheezle56]

What's your muzzle device?

[StuckInTheP.R.O.Ca]

So much fail in that statement... only >40 grain varmit rounds.

So you don't think a 7:1 ( 7 revolutions in 1 inch) twist rate is a bit excessive.

Rig is a Aero Precision complete upper M4E1.
16" CMV 5.56 mid length barrel, 7:1.

[Devilmonkey89]

Light weight bullets and a fast twist will not show a positive result.

I shoot 55 grain in a 1/7 barrel and so does a ton of CG users, and no tumbling reported.

[Kwikvette]

No Bueno.

25 yards and shooting various types of ammo, not really sure what you're doing?

Post a target, and shoot one type of ammo. Repeat for all different types and see if only one keyholes or all of them.

Report back.

[randomthought]

I've got no problems with 55gr. Had pretty good results at 50 yards on a red dot with with prvi m193 out of my 1:7. Haven't tested accuracy of 62 grain recently, but i know m855 was terrible.

[damon1272]

No Bueno.

25 yards and shooting various types of ammo, not really sure what you're doing?

Post a target, and shoot one type of ammo. Repeat for all different types and see if only one keyholes or all of them.

Report back.

^^^This. I think your problem will be with the IMI. But shoot one brand per target to isolate which one is giving you the problem. Were you having cycling problems also? Those bullet weights are fine for that twist.