AR Keyholing

[SC_Dave]

Today is the first time I've noticed this. Any help with a diagnosis is appreciated.

Info:
55 grain FMJBT
24.5 grains Ramshot TAC
Mixed brass
Rifle DDM4V11 16 in 1:7 twist
The rifle/barrel has a little over 1500 rounds on it.
Target at 25 yards

I circled a couple but as you can see there are several.



Thanks all.
David

 

[bihj]

Try a heavier bullet.

 

[horsey300]

Today is the first time I've noticed this. Any help with a diagnosis is appreciated.

Info:
55 grain FMJBT
24.5 grains Ramshot TAC
Mixed brass
Rifle DDM4V11 16 in 1:7 twist
The rifle/barrel has a little over 1500 rounds on it.
Target at 25 yards

I circled a couple but as you can see there are several.
View attachment 902790
View attachment 902791

Thanks all.
David

What's your barrel twist?

 

[SC_Dave]

What's your barrel twist?

1:7

 

[Nature Boy]

Have you cleaned it real good lately?

Check the crown?

 

[Nature Boy]

Try a heavier bullet.

That’s something to check too. 1:7 is a lot of twist for a 55g bullet, but a lot of people shoot that combo without a problem

 

[illinoisburt]

Check your flash hider/muzzle brake isn't slightly loose or off centered. If you see any shiny spots inside it you may be getting strikes which will definitely cause unstable flight.

 

[SC_Dave]

Check your flash hider/muzzle brake isn't slightly loose or off centered. If you see any shiny spots inside it you may be getting strikes which will definitely cause unstable flight.

No evidence of strikes, it's good and tight as well.

 

[SC_Dave]

Have you cleaned it real good lately?

Check the crown?

The crown looks good, no evidence of scratches or dings. There was a good bit of carbon not on, but outside of the crown. It doesn't make sense to me that it would effect the bullet where the carbon resides but I'm going to clean it anyway. The barrel looks clean but again I'm going to clean it anyway.

 

[TonyAngel]

That is unusual for a DD rifle. Are you using .223 data or 5.56 data? If memory serves, your charge weight is on the low side for either one. Recheck your data and kick the charge up some. 1/7 is a pretty fast twist rate and maybe the 55s need to get moving a bit to stabilize. I’ve always loaded to duplicate M193 so have no experience with slow moving 55s.

If this just started happening, I doubt it’s your barrel. 1500 rounds in a DD barrel ain’t nothing.

 

[TonyAngel]

Try a heavier bullet.

I doubt that this is the problem. That rifle should spit 55s just fine.

Unless your projectiles are defective. What are they? Pulls if some sort?

 

[TonyAngel]

I also doubt that it needs cleaning. It’s an AR with a chrome lined barrel. It can go many thousands of rounds without cleaning. I’d concentrate on the ammo, assuming that nothing on the rifle has loosened up.

 

[SC_Dave]

That is unusual for a DD rifle. Are you using .223 data or 5.56 data? If memory serves, your charge weight is on the low side for either one. Recheck your data and kick the charge up some. 1/7 is a pretty fast twist rate and maybe the 55s need to get moving a bit to stabilize. I’ve always loaded to duplicate M193 so have no experience with slow moving 55s.


If this just started happening, I doubt it’s your barrel. 1500 rounds in a DD barrel ain’t nothing.

Using .223 data. According to Western 55 gr FMJBT start 22.3 max 25.8, so I'm in the middle I guess.

It started today for the first time, at least that I've noticed......

I doubt that this is the problem. That rifle should spit 55s just fine.

Unless your projectiles are defective. What are they? Pulls if some sort?

New, not pulls. From Eveglades Ammo - Version 4 223 55Gr FMJ BT

I also doubt that it needs cleaning. It’s an AR with a chrome lined barrel. It can go many thousands of rounds without cleaning. I’d concentrate on the ammo, assuming that nothing on the rifle has loosened up.

I've found nothing loose thus far.

 

[mavracer]

Does it do this with factory 55s?
Are you crimping them?

 

[SC_Dave]

Does it do this with factory 55s?
Are you crimping them?

Prior to today it's never done it with any round that I know of.
The rounds I shot today were not crimped. Would no crimp have this effect?

 

[TonyAngel]

First get some factory stuff and check results. Confirm it’s the ammo.

 

[TonyAngel]

In any case, something is out of whack and in my experience DD makes a helluva rifle. I’m seriously wondering if it isn’t the projectiles themselves. .223 is one if the easiest non finicky cartridges to load for.

 

[SC_Dave]

In any case, something is out of whack and in my experience DD makes a helluva rifle. I’m seriously wondering if it isn’t the projectiles themselves. .223 is one if the easiest non finicky cartridges to load for.

I have some 55 gr .224 RMR FMJ-BT that I could load and try. Can you or anyone else confirm my load of 24.5 is within parameters according to Western's site. Just to be sure I'm not doing something dumb.....

 

[mavracer]

Prior to today it's never done it with any round that I know of.
The rounds I shot today were not crimped. Would no crimp have this effect?

No crimp is probably not the cause I asked because too much can be.
I suspect it's something with seating or damage when chambering. With a 1 in 7 twist the 55s are over stabalized if they get a little crooked seating it can cause issues.

 

[climbnjump]

Is there a backstop behind the target? A berm perhaps, with "stuff" in it? There are a couple of holes in the target that don't appear to be from bullets.

And you've got more than two dozen normal looking bullet holes. Since you've ruled out muzzle brake strikes, I can't think of any reason why you'd get only a few keyholes out of a couple dozen shots.

Also, if you could shoot the loads at a longer distance, say 50 yards, there would be more keyholes if that is what is actually happening.

 

[horsey300]

I have some 55 gr .224 RMR FMJ-BT that I could load and try. Can you or anyone else confirm my load of 24.5 is within parameters according to Western's site. Just to be sure I'm not doing something dumb.....

You're at the bottom end.... For a fmjbt, 24(ish) is the minimum, have you worked up a full ladder? ETA, don't know what brass you're using, but first pic is for 5.56.. other 2 are .223 as that's the data requested.

 

[illinoisburt]

Just to confirm - not mag dumping the rifle or super-zealous cleaning with a steel rod from the muzzel, right?

As for ammo, if neck tension is light and no crimp it is possible for boattailed bullets to be set back and misaligned in the case mouth when chambering if things arent aligned properly. Have you experienced and failures to feed?

 

[SC_Dave]

Just to confirm - not mag dumping the rifle or super-zealous cleaning with a steel rod from the muzzel, right?

As for ammo, if neck tension is light and no crimp it is possible for boattailed bullets to be set back and misaligned in the case mouth when chambering if things arent aligned properly. Have you experienced and failures to feed?

Thanks. Nope, no mag dumps, no excess cleaning either. I mostly just use a bore snake and my cleaning rod is brass. Also no failure to feed issues.

 

[SC_Dave]

You're at the bottom end.... For a fmjbt, 24(ish) is the minimum, have you worked up a full ladder? ETA, don't know what brass you're using, but first pic is for 5.56.. other 2 are .223 as that's the data requested.

Thanks! I have mixed brass so I've been loading for .223

Also just to be sure I'm not missing something, this what I find under
223 Remington > Ramshot TAC > 55 HDY BT-FMJ 23.2 3,018 25.8 3,293

Help me be sure I'm not looking at something wrong horsey300 please.
Sorry, I don't know how to do screen shots so I copied and pasted.

 

[SC_Dave]

Is there a backstop behind the target? A berm perhaps, with "stuff" in it? There are a couple of holes in the target that don't appear to be from bullets.

And you've got more than two dozen normal looking bullet holes. Since you've ruled out muzzle brake strikes, I can't think of any reason why you'd get only a few keyholes out of a couple dozen shots.

Also, if you could shoot the loads at a longer distance, say 50 yards, there would be more keyholes if that is what is actually happening.

Thanks. The target was at 25 on a 50 yard range so the berm was 25 away. I see what you are saying and some do look strange but I attributed that to tumbling. I can easily set up at 50 and try another mag.