A little Confirmation, Please...

[tsyarnall]

So, I bought a 6PPC rifle from a local gunsmith. Well known locally and has won a ton of local BR matches: short (100 & 200), mid and long range. Remington 700 action with a Bartlein barrel that he chambered. Had 100 cases of Lapua already Fire formed and 21 that he loaded for the rifle (the cases didn’t look fresh to me). He made it to shoot this year, but health issues caused the sale.
I had a couple of issues getting started. Scope issue 1st time at the range. 2nd trip to the range, I shot 2 or 3 then a case stuck and made that a short trip. After the stuck case I pulled the rest of the pre-loaded ammo and reloaded my own.
I started a 27.0 of VV n133, 64 gn Column Bergers .020 off the lands, with .003 of neck tension. Shot (2) at 27.0; 27.5; then (3) at 28.0; 28.3; 28.6; 28.9. At 29.2 I had a pierced primer.
At home I started trying to figure out my issue. The fellow I bought the rifle from said that the barrel had a .263 neck and the cases were turned to give a .260 neck loaded. The ammo is .260 loaded and after checking my spent casings, so is the neck on the barrel. The bore, chamber, lugs, everything had been properly cleaned and prepped to shoot. I have added a couple of pictures. One loaded with caliper and one of the cases that I loaded and fired in the rifle. I guess the cases may have sprung back .001 of an inch, but doubt it sprung back more. I checked all of the cases, both loaded and those that I had shot at the range that day and they all measure the same.
At this point I think the best thing would be to turn the cases down another .003 or .004 and start again. I’m open to suggestions, though.

Scott Y

 

[tsyarnall]

Loaded

 

[jimmymac]

Try measuring with a mic. Measure the fired brass close to the case mouth and measure the loaded ammo where the bullet pressure ring is.

 

[tsyarnall]

.260

Scott Y

 

[Bc'z]

Take 5 cases and turn them down, load and shoot. This should help in troubleshooting the problem

 

[joshb]

I’d cast that chamber. Get some Cerosafe. It’s easy.

 

[madmixerman]

I think if you turn cases another 3or 4 thousands the necks would be too thin. If I am figuring correctly, a loaded round is .260 and bullet is .243 that means the neck is turned to .0085" per side. Pretty thin already . IMO

 

[jackieschmidt]

What is the firing pin protrusion on the bolt face?

none of those loads should produce any thing near high pressure with a 64 grn bullet.

i have never seen a 6PPC with a neck smaller than .262, so your loaded round would be fine even in that, much less a .263 neck.

This leads me to believe there is a mechanical problem.

are there any other pressure signs besides the pieced primer?

 

[Walt Krafft]

How is the case overall length?

 

[timeout]

Are you getting hard bolt lift? Pierced primer may simply be in need of an @carlsbad bushing and firing pin job to eliminate that. I agree with @joshb that you should do a cerosafe chamber cast to be certain of the actual chamber neck diameter.

 

[Ccrider]

What is the firing pin protrusion on the bolt face?

none of those loads should produce any thing near high pressure with a 64 grn bullet.

i have never seen a 6PPC with a neck smaller than .262, so your loaded round would be fine even in that, much less a .263 neck.

This leads me to believe there is a mechanical problem.

are there any other pressure signs besides the pieced primer?

Is this so even with a Remington action?

 

[tsyarnall]

First, thanks to all of you for your help. I just wanted to make sure that I wasn’t TOO crazy.

*Yes, it’s a Remington 700 action.

*No, I really didn’t have any heavy bolt lift, but the primers were starting to flatten. Although, it wasn’t showing any ejector marks or smears on the brass.

*And I should have already had the bolt bushed.

**Joshb, I may be going the wrong way about it, but I had just ordered a set of pin gages to see exactly what neck size I have. I’ll do a casting of the chamber, also.

*This brass may have been shot a bunch of times and I can almost guarantee it has never been annealed. So, it could have a lot of spring-back. However, if the neck is that tight, it could be causing the pressure issues and I won’t know until I know the neck size of the barrel.

*Once I know what I have, I’ll just turn some new brass. Fire-form the cases, get the firing pin bushed and the problem should be solved. I hope!!! This rifle has been one issue after another.

Scott Y

 

[bainp]

If you anneal several cases and load them well below the point that you pierced the primer, fire them and them mike the neck. This will give you a much better idea if the chamber has a tight neck or not. If chamber neck is tight, the cartridge neck will still be 0.260 after firing, if chamber neck is not so tight the cartridge neck will expand to pretty much the size of the chamber neck and only spring back a tiny amount.

 

[tsyarnall]

I’m sure it’s not a .260 neck. The thing is I learned a lesson. Don’t believe any thing. Or as President Ronald Reagan said, “Trust, but verify......”

Scott Y

 

[jimmymac]

How is the case overall length?

Great question Long brass could be an issue.

 

[fkimble@charter.net]

What primer are you using?

Frank

 

[Tokay444]

If you need to measure with a caliper, measure up near the top of the jaws.
I’m guessing a bullet doesn’t drop freely into a fired case.
Do you have the means to anneal?

 

[butchlambert]

Weak firing pin spring, excess headspace, and maybe, no, you need to bush the bolt anyway.
In the olden days we used .261 necks.

 

[AlNyhus]

If that rifle was here, the first things I would do are:

-Determine the chamber neck diameter using a gauge pin.
-Determine the chambers length using a case length plug.

Until you know those dimensions, everything else is just speculation. And that's how people get into trouble. You have to know.

Once you know those two things, you can move forward.

Good shootin'. -Al

 

[tsyarnall]

Again, thank you to everyone for their help. I do appreciate it.

* Walt Kraft & Jimmymac: case length is 1.490”

* fkimble : primers are CCI BR-4

* Tokay444 : no, a bullet will not drop in one of the fired casings

* AINyhus : I agree

Here is a picture of the primer.

Thanks to all,

Scott Y