6 PPC Norma Brass Issue

[DaWhit]

This is a new Bartlein 4 groove 13.5” twist .268 neck, 6 PPC barrel just picked up the other day.

Loading 25gr N133 in Norma 6 PPC brass, just bought a couple weeks ago from Drifters Gear, with a Sierra 60gr flat base bullet to blow out the brass and break in the barrel. Loosing half the brass due to what looks like a small fracture .306” up from the base of the case.

Wondering if anyone has had a similar issue? Cause? New PPC shooter so any help much appreciated.

 

[gunsandgunsmithing]

Looks just like incipient case head separation. Was the brass new, unfired and how much are you bumping the shoulders back. And if not first firing, how many before this shows up? Are they actual cracks or a line that might or might not become a crack?

 

[DaWhit]

It feels like a crack when you rub your thumb nail over it.
First firing, so no bump. Just seated the bullets 15 into the lands.

 

[gunsandgunsmithing]

It feels like a crack when you rub your thumb nail over it.
First firing, so no bump. Just seated the bullets 15 into the lands.

Suck it! Lol! I kinda doubt its a crack on new brass but maybe. If so, I'd check or have someone go over the gun well either way. Might be way too much case protrusion and that can be a safety concern. If you can hang your nail on it, I suggest getting it looked at. How hot is the load? Pressure is not normally the cause of a crack there but it could be if it's hot enough. Even if it's not fully cracked, it's talking to ya. I'd listen to it.

 

[DaWhit]

Suck it! Lol! I kinda doubt its a crack on new brass but maybe. If so, I'd check or have someone go over the gun well either way. Might be way too much case protrusion and that can be a safety concern. If you can hang your nail on it, I suggest getting it looked at. How hot is the load? Pressure is not normally the cause of a crack there but it could be if it's hot enough. Even if it's not fully cracked, it's talking to ya. I'd listen to it.

Mid 2800fps.

 

[gunsandgunsmithing]

Mid 2800fps.

That's way, way off on speed and powder unless an AR15 or something. A good bolt gun should easily be in the 3400fps range...easy. I'd talk to Drifters Gear. Good people.

 

[djporter]

Suck it! Lol! I kinda doubt its a crack on new brass but maybe. If so, I'd check or have someone go over the gun well either way. Might be way too much case protrusion and that can be a safety concern. If you can hang your nail on it, I suggest getting it looked at. How hot is the load? Pressure is not normally the cause of a crack there but it could be if it's hot enough. Even if it's not fully cracked, it's talking to ya. I'd listen to it.

Nailed it

 

[ShtrRdy]

I would guess the brass has a thin ring. Several years ago I had some Remington 223 brass that did the same thing. I had to throw out half the pieces.

 

[Larry Koch]

pma reloading is taking orders for Alpha brass 6ppc.

NO LIMIT. Alpha 6mm PPC (100ct)
only your wallet.

 

[Tim Singleton]

Listen to Mike
you did say new barrel. Please check the cone depth and case head support

 

[BartsBullets]

Listen to Mike
you did say new barrel. Please check the cone depth and case head support

^^^^^
What Tim Said!

 

[jimmymac]

What Bart said that Tim said that Mike said.

 

[Peterson1]

Confirm a case seperation about to happen??
Run a paper clip streightened on the inside of the case
If you feel any irregularity on the inside of the case at this area of suspicion its time to toss the case!!!!!!
Its always a good idea "to get a second opinion" ie; Gunsmith
You need to know the cause before more cases are involved($$$Lost) or worse!!

 

[dat]

What Bart said that Tim said that Mike said.

Yes on the above!
One other idea comes to mind. Are you certain that the bullet is jammed enough to hold the brass on the boltface during ignition? If not, the case could be pushed far enough ahead with primer strike to allow for the stretching coming back. Don't know at your velocity if the pressure would be high enough to stretch the case as much as shown, but a possibility. Good luck!

 

[deadeyemike]

What kind of receiver is this built on? That load seems really light with 133. You can get high pressure from too light of a load as well as too hot of a load.

 

[DaWhit]

What kind of receiver is this built on? That load seems really light with 133. You can get high pressure from too light of a load as well as too hot of a load.

Panda action.

Pretty sure the chamber is cut too deep after checking my spent brass to spent brass from a couple other guns chambered by the same company.

Thanks for all the replies and help.

 

[deadeyemike]

Can you see inside the chamber and see if there is a ring around it? If a small chip got under the reamer it could leave a ring around it. Did you check the inside of the case to see if you could feel it there?

 

[DaWhit]

Can you see inside the chamber and see if there is a ring around it? If a small chip got under the reamer it could leave a ring around it. Did you check the inside of the case to see if you could feel it there?

Yeah you can feel it inside the case. Chamber looks fine with the borescope.

 

[gunsandgunsmithing]

Yeah you can feel it inside the case. Chamber looks fine with the borescope.

I'd get it fixed before shooting more. Too much unsupported case might be the, or one of, the most critical aspects of a gun build, from a safety standpoint. I've seen them that looked way worse but your load is super mild, thankfully. No need to mention names but is the smith reputable? A lot of times people just put way too much chamfer at the end of the chamber but that's just as bad as too short. It can be a mistake or it can be ignorance. This is one thing that separates a very good machinist from a qualified gunsmith. Just knowing the whys and what fors matters. This is NOT an area where clearance is just clearance. In this case it matters a whole lot. Too much unsupported brass means you've got nothing more than say .025-.030 of brass between you and 65,000psi. There are failsafes in most guns but they are not 100%. Just meant to minimize damage, not stop everything.

 

[DaWhit]

I'd get it fixed before shooting more. Too much unsupported case might be the, or one of, the most critical aspects of a gun build, from a safety standpoint. I've seen them that looked way worse but your load is super mild, thankfully. No need to mention names but is the smith reputable? A lot of times people just put way too much chamfer at the end of the chamber but that's just as bad as too short. It can be a mistake or it can be ignorance. This is one thing that separates a very good machinist from a qualified gunsmith. Just knowing the whys and what fors matters. This is NOT an area where clearance is just clearance. In this case it matters a whole lot. Too much unsupported brass means you've got nothing more than say .025-.030 of brass between you and 65,000psi. There are failsafes in most guns but they are not 100%. Just meant to minimize damage, not stop everything.

Yeah it is a reputable company, did numerous barrels for guys at our club with no issues, I am sure they will make it right.
Calling them first thing Monday and shipping it back.