Issues with 223 Keyholing???

[alexisjohnson]

Hey guys,
So i've probably loaded around 1000 rounds in 223 during the past year but for the first time, i'm having issues with my 223's keyholing.

The keyholing starts at around 15 yards (at 10 its basically nonexistent) and it gets progressively worse. By 25 yards, some of the shots are not even within the 8 inch target. The rifle is an ar (BCM upper) that works just fine with factory ammo. I know for a fact its capable of shooting at least 1 moa at 100.

As far as the cartridges go, they are Wolf and Federal Brass, loaded with Berrys bullets, with CCI primers and TAC powder at 23.3. COAL is 2.23. Crimp is within spec (i pulled a bullet and checked it for deformation but it was fine). I barely crimp anyways.

Any ideas whats going on?

[Devilmonkey89]

Barry's plated? You might be pushing them too fast causing the copper plating to come off the lead core causing said issue. My best guess.

Edit: seems like barry's is a FMJ bullet. Did you check bullet diameter? Could be out of spec bullets wobbling down the barrel.

[bazineta]

Keyholing at about 15 yards is typically what happens when you shoot M855 62-grain bullets in a 1:12 twist barrel, designed for 55 grain. What's your twist rate, and what weight are the bullets?

[alexisjohnson]

55 grain berrys and my twist rate is 1/7.

I checked the diameter on the bullets and they're fine as well...

[bazineta]

Not the twist rate then. I'd check for barrel badly fouled, bullets out of spec (too small), or damage to the crown, in that order.

[SkyHawk]

+1 fouled barrel

[alexisjohnson]

Barrel is clean as a whistle. I only have 1.5k through this upper and i clean it every 500 or so.

The only thing i can figure is perhaps i'm putting too much powder and the FMJ's can't take it (for whatever reason)? 23.3 is pretty close to max according to my hornady handbook. With that said, there are no pressure signs that i can see...

[SkyHawk]

Leaded barrels look clean as a whistle. We're not talking fouled with powder.

So drop the charge 10-20% and test your powder theory. And for the love of everything holy test with some quality factory ammo. If it doesn't work, get ready to get the lead out.

[alexisjohnson]

I'm going to take another Ar, as well as factory ammo and see whats what. I'll update you guys on what happens.

[baih777]

Try a diffedent bullet or some factory ammo. If you get the same results, barrel is shot out.
If the results shoot better with different bullet. Then lower charge to see if you can get the berrys bullet to work.

[ironhorse1]

Barrel is clean as a whistle. I only have 1.5k through this upper and i clean it every 500 or so....

You only clean after 500 rounds? Wow! If it shot good before then something has changed.

I would suggest a good scrubbing with JB Bore Paste. I think that you will really be surprised at the amount of fouling left in the barrel.
Plan on a long session and many patches before it is really free of fouling.

irh

[noylj]

Did you measure your actual groove diameter?
Keyholing is almost always due to bullets too small for the barrel's liking.
The groove diameter should be 0.224-0.226". I find that plated bullets, just like lead bullets, do best if they are at least 0.001" over actual groove diameter, meaning I would be using bullets in the 0.225-0.227" range, after measuring the actual groove diameter. Jacketed bullets don't seem very sensitive to groove diameter, as long as the rifling takes a good "grip."
Buy some good jacketed bullets and see how they work.

[DueceMcGurk]

+1 on IronHorse suggestion.

[dwalker]

What muzzledevice are you using? I have seen carbon buildup or damage cause strikes that led to keyholing.

Have you changed ANYTHING related to the crown of the muzzle?

[dwalker]

Did you measure your actual groove diameter?
Keyholing is almost always due to bullets too small for the barrel's liking.
The groove diameter should be 0.224-0.226". I find that plated bullets, just like lead bullets, do best if they are at least 0.001" over actual groove diameter, meaning I would be using bullets in the 0.225-0.227" range, after measuring the actual groove diameter. Jacketed bullets don't seem very sensitive to groove diameter, as long as the rifling takes a good "grip."
Buy some good jacketed bullets and see how they work.

Berrys are "good plated bullets" in .224 sizing.