neck dimension

[dunraven]

I bought a used 6ppc rifle with a '.262 neck'. The fired brass measures .260, consistently. Does that mean that the rifle really has a .260 neck?

 

[RMiller]

The brass springs back a little. If it didnt you would have a hard time removing it from the chamber. .260 sounds about right for a .262 neck.

Ryan

 

[mikecr]

It means the loaded necks measured ~.261 with ~.001 of tension from sized necks at ~.260.
On firing the necks go to .262, then spring back to the .260 they are,without bullets seated).

This is normal with tight clearances
I shoot a tightneck 26 cal with a chamber neck at .291
My loaded necks measure .290
When I pull them from the chamber they measure .289
Technically, I do not even need to neck size on reloading.