AR Keyholing

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55 HDY BT-FMJ 23.2gr. 3,018 25.8gr. 3,293 PSI 54,894 . That's Ramshot Tac load data for Remington .233 from the Western Powders Handloading Guide Edition 7.0. Looks like you are right about in the middle.
 
Bullet diameter too small or baffle strikes was what first popped into my head.

My buddy just loaded some Everglades 62gr fmj. They shoot something awful. No tumbling but they produce horrible groups.
 
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.
From the data I screenshot, for the Hornady fmjbt 55 gr, 24.3 is the recommended start load with a max of 27, this is from their data sheet I downloaded 2 days ago, I don't know what version you have, so I won't say you're reading it wrong, but I'm not seeing the same numbers you are.....
 
From the data I screenshot, for the Hornady fmjbt 55 gr, 24.3 is the recommended start load with a max of 27, this is from their data sheet I downloaded 2 days ago, I don't know what version you have, so I won't say you're reading it wrong, but I'm not seeing the same numbers you are.....
OK, thanks horsey!
 
I had some tumblers in a prior 223 barrel w/ 50gr "Zombie Max". Also had the 55gr version of same bullet and had no problems.,
Never did nail down the exact problem. Could have been several factors working in tandem though.

Looking back, I was loading them a bit stout for a 223, but never exceeded 5.56 data.
I eventually was blessed with a bit of a clue,,,

(The following is a random pic off the net, not mine.)

bh.JPG

I'm certainly no expert, but I interpreted my similar swirls to be traces of molten lead coming through the exterior surface of the bullet, either because the exterior surface was defective or it was somehow compromised after I pulled the trigger.

(Didn't see any swirls in the OP's pic, but early on, I also didn't notice any swirls in any of my targets that had tumblers)

I figured it was just a bum batch of bullets so I 'shelved' the remaining 50 gr's back in my reload room.

Flash forward a year or 2. I had a new barrel (and a bit more reloading experience)

Couldn't tell ya exactly what changed, but those same 'shelved' bullets shot just fine, w/zero keyholes.

About the only thing one may derive from all this was that the 1st 'bullet/barrel/reloader' combination didn't work out as intended, but same "bullet/different barrel/ more experienced(???) reloader" combination did work as intended.

How does any of this relate to the OP's dilemma? Other than 'tumbling', it may or may not.
 
OK, thanks horsey!
Just be safe and work up slow with 5 shot groups in .3 gr increments from 24.3 to 27 and see if it straightens out for ya, I've had keyholes only when understability was a factor, your twist is fast enough, so shouldn't be an issue at all really, BUT it's not impossible and in my experience, if the barrel is adequate, then all that's left is speed.......this may not be powder charge alone, addin a crimp will increase pressure, a short throat/too long oal will increase pressure, etc, lots of factors at play, so be mindful of your gun and how it's "acting" watch for the red flags, and if you hit 27 gr and still have keyholes from a clean barrel (especially after the first shot or 3) then you have different problems than charge weights...... Good luck sir!
 
I’d start with buying a box of factory ammo and see what it does. A cheap and easy way to eliminate the rifle being the cause or focusing in on it as the cause.

When they shoot right or not, we have a direction to move towards.

If they shoot fine, next thing would be to pull bullets and see if you are causing damage to your reloads in the process.

If they don’t, you can look to the barrel as the prime suspect.
 
You have more than enough twist for stability.
You are within published data. Over what I load for a 50grn Vmax and TAC in a seven twist 5.56.
The circles you have made are on very tight groups, from what I see. (Not to brag...;))
The ones that do look key-holed are very sideways, but there are no other varying degrees of tumble, also a sign of not being at the edge of stability, which we know it is not.
Since you have a nice rifle, but are using very poor bullets, I shall wager that it’s not the barrel.

Which leaves us with the bullet.
How do they measure up?
Did they feel like they seated easier?
Were any tested for setback? That won’t make them keyhole, but it’s not great for accuracy.

(Hmmm... unless it was very deeply set and when fired, the powder had enough pressure to ignite, did not squib out, blew enough powder past the bullet to lessen the pressure, leading to velocity loss and causing instability, while still capturing enough gas to still operate the rifle for the next round.

I don’t do perfect storms. Especially not multiple times...;))

Sorry, back to the bullet.

Which is not know for accuracy from that company.
And, if too small, could skate the rifling and fail to stabilize.
Hornady is known for consistent FMJs. Though I would take a soft point in an instant for accuracy.

When you have a DD and can handload for less, why not use the best?
(Well, better than what you have. They lost me at “Slightly more weight and dimensional variations than version 2...”:D)
 
In a safe place, manually cycle a number of the rounds through the gun without firing. Let the bolt slam like it would when shooting so that it properly feeds from a loaded magazine. inspect each round after you eject them to make sure the bullet is not getting pushed back into the case on feed. Since you said you had no crimp it is a possibility.
 
Wow, what make of barrel is that?

That is from a Norinco SKS barrel (I was wondering why it was so horribly inaccurate). I'd certainly expect MUCH better quality from a US manufacturer but it is a remote possibility with any chrome lined barrel.
 
I'm certainly no expert, but I interpreted my similar swirls to be traces of molten lead coming through the exterior surface of the bullet, either because the exterior surface was defective or it was somehow compromised after I pulled the trigger.

I have seen that when plated bullets are giving up and have seen bullets completely disintegrate if they are thin jacketed bullets, intended for a 1:14 barrel but used in a 1:7; however, the OP is using FMJ’s unless something was wrong with them before he loaded them or they were damaged in the process they should run and shoot just fine.

I’d still introduce a “control” group of ammunition that’s made by a reputable manufacturer. 20 rounds of cheap FMJ later, we could have a 50% better chance of finding the actual cause of the OP’s problem.
 
the "word" was that the new 5.56 bullet was designed to tumble

Yes, but after impact.

It takes a fair amount of luck to hit the target if they tumble beforehand.

have seen bullets completely disintegrate if they are thin jacketed bullets, intended for a 1:14 barrel but used in a 1:7;

Such as Hornady's 50 Sxsp. For every half grain of powder over the starting load I lost 25 yards of distance before they vaporized midair.

Great if you want to keep the bullets from leaving the property.
Not so great if you misjudge the target distance by two feet.:)
 
I have seen that when plated bullets are giving up and have seen bullets completely disintegrate

Funny you mention this @jmorris , I have seen this recently as well. A cloud of "dust" 15 - 25 yards down range with no impact on steel that was an easy to hit target. Disintegration for sure.
 
Was that target attached to a rigid backer that was not all shot up? If the target was moving around in the breeze or just attached at the top and allowed to move you might see what appears to be keyholing and it is the paper moving when struck.
 
Was that target attached to a rigid backer that was not all shot up? If the target was moving around in the breeze or just attached at the top and allowed to move you might see what appears to be keyholing and it is the paper moving when struck.

Yes it had a rigid backer, in fact I shot a few more later on a double thickness cardboard backer only with the same result..
 
UPDATE:

I'm suspect of the projectiles.

Target was at 25 yards and consisted of a rigid cardboard backer so I could clearly see any keyholes or the lack thereof. I divided the backer into 3 sections with a sharpie.

Shot 20 rounds slow fire of factory ammo 55gr, slow fire. No keyholes. Barrel/rifle eliminated.

Shot 20 reloads slow fire, no crimp, 55gr Everglades projectiles, 7 keyholes.

Shot 20 reloads slow fire, with slight crimp 55gr Everglades projectiles, more keyholes.

I loaded 30 rounds this evening using RMR 55gr FMJBT and I'll test these tomorrow and report back here. If I have no keyholes with these 30 rounds I'm going call it bad bullets.
 
Have you measured the dia of the bullets making sure there 0.224". I've received bullets over the years that were under size, 0.2235-0.223" . Normally you will detect a difference in neck tension if your paying attention..

I did, they varied from .223, .2235 and .224
 
I did, they varied from .223, .2235 and .224

Yes, yes. But what of the bug?

Seriously, though there’s your problem. Different friction amounts leading to not great groups, along side some so small they “ don’t take”, and keyhole.

Were the RMRs pulls or brand new? I can’t wait to see how they shoot...:thumbup:
 
Yes, yes. But what of the bug?

Seriously, though there’s your problem. Different friction amounts leading to not great groups, along side some so small they “ don’t take”, and keyhole.

Were the RMRs pulls or brand new? I can’t wait to see how they shoot...:thumbup:

The RMRs are new. I'm eager to see as well.
 
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