Lapua brass crimp at shoulder

[Bigwheels]

Been using cheaper brass for decades but bought some new Lapua for my 300WM & when sizing with a Redding -S die bumping .002 it is putting a crimp right at the neck/shoulder. I can feel it when seating & I can measure it inside right at the base of the neck. This is causing runout & inconsistent neck tension. My Win & PPU brass don't do this.
Anyone know what is causing this?
Thanks.

 

[918v]

Lapua 300wm brass has really thick necks. If you’re using the same bushing as for your Winchester brass then you’re over sizing the neck.

 

[Bigwheels]

I'm not using the same bushing. .331 for the PPU & .337 for the Lapua.
It does this without any bushing in it too.
Always in the same place just at the neck/shoulder junction..002" smaller there than the bushing sized area.

 

[918v]

Maybe it’s just the nature of the brass. Is the seating pressure ok? Does the loaded round have enough clearance in the chamber? If it’s ok then just go with it.

 

[BrienM]

Check and make sure your seat die isn't screwed down to far causing the seat die to try and "crimp" in the bullet.

 

[AllenOne1]

I'm not using the same bushing. .331 for the PPU & .337 for the Lapua.
It does this without any bushing in it too.
Always in the same place just at the neck/shoulder junction..002" smaller there than the bushing sized area.

Is your bushing getting the neck area sized down small enough? Moving up .006 in bushing size seems like a bunch. That would indicate that your Lapua brass is .003 thicker than the PPU brass.

Are you using a button or mandrel to finish size the neck? If you are it would seem like it should be pushing the brass back out in the neck/shoulder area.

 

[Bigwheels]

The PPU brass has .012" neck & the Lapua is .015"
Since it does it without a bushing in the die the bushing size is irrelevant.
The shoulder is bumping back only .002"