.264 Win Mag neck sizing - is this far enough?

[Uncle Ed]

What is your case neck runout after sizing the neck diameter down .010 with your bushing die?

What is your neck thickness variations on your unturned necks?

Have you ever trimmed your cases to remove the case mouth peening we see on your case mouths.

The main reason so many reloaders use the Lee collet neck sizing die is they get less runout than a bushing die.

 

[Shinbone]

Uncle Ed - good questions! Thanks for asking. I will make some measurements to find out. I do have a few Lee Collet dies, but not for .264WM

On the case mouth peening question, I have not done any trimming, yet. Since I am so new at reloading, please describe what that peening looks like so I can identify it for myself. Thanks!

 

[Shinbone]

Comparing case mouth runout of fired .264WM cases on a 21st Century concentricity gauge. Five non-sized cases vs five cases neck-sized by various amounts. Case mouth OD before sizing averaged 0.301 with less than .001 variance:

Unsized: .002, .002, .002, .002, .002

Sized from .301 to .290: .004, .004, .006, .007, .003

Sized from .301 to .295: .002, .002, .001, .001, .002
Then size from .295 to .290: .003, .003, .002, .003, .003

A good learning experience for me.

Wish I had a Lee Collet die for .264WM to throw into the test.

 

[243winxb]

have a full-length die made for this chamber.

This should solve the runout problem? Maybe.