Lapua 6BR brass...Old vs New

[CoverDog]

I just measured some "new" paper box brass and some new "Blue" box. I know of the neck thickness issues with the new but I was surprised to find the following:

The new Blue box brass I have has the shoulder set back .003" compared to the old brass. 1.068" old case / 1.065" new case. This was measured in a Hornady head space gauge with Sinclair SS inserts. And the OAL was 1.556 old brass 1.553 new brass

Has anyone else found this to be true?

 

[dantiff2]

Yup I've got .004-.005 shorter at the datum line then my older brass... I'll seat hard into the lands so it stays tight on the bolt face for a good fire form.

Dan

 

[robbor]

How does neck thickness compare?

 

[6BRA]

.001 variation in neck wall thickness is typical on Lapua. I recently received a box of 6br that had 6 or 7 cases almost .010 short of trim length which was already shorter than I preferred.

 

[barefooter56]

Guys,
New brass is going to have "variations" in it as far as length , shoulder , ETC. You have to look at the chamber of YOUR RIFLE as the last FORMATION DIE the brass will go through. This may take more than one firing for the brass to get blown out to your chambers specs.

 

[NorCalMikie]

Start with knowing the measurements of "YOUR CHAMBER" and go from there.