Tight Throat?

[Pdvdh]

It would be really difficult to cut a chamber with a crook at the neck with any standard chamber reamer. I have no idea how Christensen cuts their chambers. So I left that in there as one of two possible causes.
My money is on crooked, non-concentric reloaded cartridges.

 

[Nvhunter92]

It would be really difficult to cut a chamber with a crook at the neck with any standard chamber reamer. I have no idea how Christensen cuts their chambers. So I left that in there as one of two possible causes.
My money is on crooked, non-concentric reloaded cartridges.

So how could I remedy this with my reloading practices? I understand I need a concentricity gauge to check my results and will buy one shortly. That's part of the reason I got gold metal match neck bushing and seating die

 

[Pdvdh]

It would be really difficult to cut a chamber with a crook at the neck with any standard chamber reamer.

However I have seen gunsmiths figure out ways to cut crooked chambers, which aren't concentric with the bore.

 

[Pdvdh]

So how could I remedy this with my reloading practices? I understand I need a concentricity gauge to check my results and will buy one shortly. That's part of the reason I got gold metal match neck bushing and seating die

I don't think a little bit off is causing this. Find a loaded cartridge that engages to cause the scuff on one side of the bullet, like in your photo. Roll the loaded cartridge across a table. Does the bullet wobble or run true?
Just saying, first confirm the problem before beginning the correcting of it...

 

[26Reload]

From your photo...the right side of the neck sure looks wrinkled and shorter than the left side...and a sure check would be to run a factory cartridge in the chamber and see if it get scratched up...if not than definitely the problem is in the die....

 

[1Moose]

Interesting problem. Quick question, if you rotate the cartridge 180 degrees and rechamber, would you get scuffs on the same side of the bullet, or at that point would you get scuffs on the other side?

 

[Mikecr]

It does sound like the throat/bore is offset from the chamber.
New cases just provide so much slop that the ammo works.

 

[Nvhunter92]

Interesting problem. Quick question, if you rotate the cartridge 180 degrees and rechamber, would you get scuffs on the same side of the bullet, or at that point would you get scuffs on the other side?

If I rotate the cartridge the scuff marks appear at the exact same spot, overlapping the previous marks

 

[Pdvdh]

Interesting problem. Quick question, if you rotate the cartridge 180 degrees and rechamber, would you get scuffs on the same side of the bullet, or at that point would you get scuffs on the other side?

Yup. If only one or the other is non-concentric (ammo versus chamber), that will help ID the cause as more likely ammo, or chamber.
I believe this is so non-concentric that rolling ammo across a flat surface will visually ID the cartridges as the problem, if they are the source of the crooked.

If you wanna measure concentricity down to 0.0005", you'll need a gauge. This is far enough off I compare it to looking down a bent arrow shaft.

 

[Pdvdh]

If I rotate the cartridge the scuff marks appear at the exact same spot, overlapping the previous marks

Your loaded cases are crooked, and this should be visible when rolling them across a flat surface.

 

[Nvhunter92]

Yup. If only one or the other is non-concentric (ammo versus chamber), that will help ID the cause as more likely ammo, or chamber.
I believe this is so non-concentric that rolling ammo across a flat surface will visually ID the cartridges as the problem, if they are the source of the crooked.

If you wanna measure concentricity down to 0.0005", you'll need a gauge. This is far enough off I compare it to looking down a bent arrow shaft.

Thanks, I will try rolling them. Just a question as I'm still relatively new. What in my picture is showing you that it is so far off?

 

[1Moose]

If I rotate the cartridge the scuff marks appear at the exact same spot, overlapping the previous marks

Given that, it seems to me that it would be an issue with concentricity of the cartridges. I'd also recommend rolling a cartridge on a flat surface and seeing if you can detect a noticeable rise and fall both at the bullet and on the case neck. I think you likely will.

 

[1Moose]

Thanks, I will try rolling them. Just a question as I'm still relatively new. What in my picture is showing you that it is so far off?

We can't see an issue with concentricity from the photo, but that would appear when the side of the case is supported by a gauge--or as we're suggesting a countertop or other flat surface--and rotated. Look forward to hearing if you see that rise / fall in the area of the bullet or even the case neck. Good luck!

 

[Pdvdh]

Thanks, I will try rolling them. Just a question as I'm still relatively new. What in my picture is showing you that it is so far off?

The magnitude (degree) of scuff on only one side of the bullet perimeter. It's tweaked over quite a bit to do that. Like a boomerang.