7-08 Lapua Brass Neck Thickness

[jlc204]

Can someone tell me the neck thickness of Lapua 7-08 brass? Trying to figure out how much clearance there would be in a .317 necked chamber.
Thanks

 

[XTR]

I don't have a ball mic, but checking the box of new brass I have here with calipers gets 14-15 thou.

 

[Santee116]

Still on my first box, but it runs .013 to .0135 with a loaded round at .311 to .3115 with a Hornady 162 BTHP.

Run-out and consistency of the brass is excellent, as usual from Lapua.

Edit: The necks were measured with a ball mic. Also, this is likely from the first run of Lapua 7-08 brass, got it when they first came out with it.

 

[jlc204]

Thank you, Gentlemen

 

[jsthntn247]

I've wondered why most 7-08's come with a 317 chamber? Mine is a custom rifle and loaded rounds Nosler brass measures .310. I'm getting blowby on to the shoulder. Shoots well though.

 

[XTR]

.317 is SAMMI spec.

If Lapua is at about .014 .284+.028= .312 With a .317 you only have .005 maybe .006 clearance if it's a .013.


Running WW brass my handloaded loaded 7-08s using WW measure .310.

I'm happy with my .317.

If you are getting blow by I'd suspect low pressures or need to anneal.