KEY HOLE PROBLEM

[Blacktailer]

That is jacket separation. Here is keyholeing.

53gr TSX 223 out of a 1 in 14 barrel at 30ft.

 

[asd9055]

wao! I am happy to say I have never seen anything like this. Maybe I am not pushing hard enough

 

[can1010]

What length barrel are you running in your 6.5 PRC. Just curious.

I am running a 28 but no brake so it is the same as a 26 with a brake. I look for loads at the top of the lower node not the upper end like a lot of people so my velocities are about the same as a 26 inch barrel

 

[asd9055]

A 28" with no brake is not the same as 26" with brake for internal ballistics and muzzle velocities. 28" with no brake would be the same as a 30" with a 2" brake. You don't count the brake

 

[can1010]

A 28" with no brake is not the same as 26" with brake for internal ballistics and muzzle velocities. 28" with no brake would be the same as a 30" with a 2" brake. You don't count the brake

the question was about my barrel length not ballistics or velocity. the velocity info. was for reference because there is more on the table if somebody wanted to chase velocity

 

[asd9055]

the question was about my barrel length not ballistics or velocity. the velocity info. was for reference because there is more on the table if somebody wanted to chase velocity

I stand corrected!

 

[DJ Fergus]

Do you think the 144 gr Berger would be a good choice?

I think the 144 would shoot well. It has a pointed tip, it may not reliably mushroom on game. It wouldn't hurt to check it for a carbon ring or clean it as if you were cleaning for a carbon ring before going to another bullet.

 

[milo-2]

sorry had trouble with attachmentView attachment 218707

I am not going to read this whole post, that is not a keyhole, your bullet is coming apart here.

 

[foul bore]

I think the 144 would shoot well. It has a pointed tip, it may not reliably mushroom on game. It wouldn't hurt to check it for a carbon ring or clean it as if you were cleaning for a carbon ring before going to another bullet.

I plan on a super clean job including carbon ring. I dont use this gun for my hunting, just steel and targets at this time, thanks

 

[budlight]

Like the other poster said. Your L looking thing is not "Key Holing" It would seem like 2900 fps isn't fast enough to blow up a bullet with 7:1 twist, but that is what is happening. the 7 twist is exceeding the design limitation of that bullet. I did it many years ago with 50 gr bullets out of 26 inch 22-250. It became a shot gun and it would plaster all over the paper at 25 yards.

Key holing like the above poster I was able to do with 55 gr 223 AR-15 with a 20 inch barrel 7:1. 3200 fps I ended up throwing the barrel away and went to 9:1 with lighter bullets and 8:1 with up to 80 gr with 20 inch barrels.

I did some research and Lilja barrels doesn't even make the 7:1 twist. So I would tend to say that 7 is not a good option at that velocity for that bullet

 

[vortech347]

The 147's blow up. There are multiple threads about it online and I have witnessed it happening more than once.

I know two different shooters with first hand experience in creedmoors and prcs.

The 144 Berger will not expand but shoots good.

140 eldm seems to be holding up. There is just something in the 147's that Hornady needs to address.

 

[Ga6570]

My X-Bolt Hells Canyon Long Range in 6.5 PRC (same rifle specs, different stock) hasn't had any issues with the 143 ELD-X bullets, I've got the reloads shooting same velocity as the factory loads @About 3008fps and I'm loving this thing. I don't have any experience with the 147 match bullets. I've only ever shot the eldx in it.

I agree the bullet is coming apart. That u shape is crazy! good luck Be safe!

 

[preventec47]

Can you please clarify, is the obvious key hole from ONE shot or TWO shots. IF two shots
then I can see two different keyholes that intersect.

 

[jarnold37]

That is jacket separation. Here is keyholeing.

53gr TSX 223 out of a 1 in 14 barrel at 30ft.

Maybe I am way off on the problem mentioned, but do remember a local gunsmith telling me of a customer that had a 22-250 in pristine appearance and the complaint that some bullets missed the target and some hit but would "keyhole." On further inspection he discovered the bore was rusted and severely pitted. Apparently the jacket was being gouged and torn and at 3800 fps the rotational velocity was causing jacket destruction in mid flight. With 14" twist and 3800 fps the rotational velocity of the bullet is 195,429 rpm. With an 8" twist and 2900 fps the rotational velocity of the bullet is 261,000 rpm. Some barrels with fast twist are possibly not hand lapped and if rust or even pits added to the mix, the bullet cannot take those kind of physical stresses.