New lapua brass issues.

[Brians356]

Ran the brass through my f/l die then expanded the necks. No issues. Seating pressure was all with in a 5-8 foot lbs. So I'm assuming that should mean consistent neck tension

Wow, you could seat those with you fingers, and pull them as well, couldn't you?

 

[Brians356]

Is that a Sinclair "oversize expander" mandrel?

 

[Cody Richardson]

The plan is I have a F/L die at Forster now getting the neck tension honed. However, I discovered the mandrel I use now gives me the perfect amount of neck tension(about 2 thou). When the new die comes in it won't be an issue anymore

 

[Brians356]

I would suggest reversing the order: expander die followed by FL resize with the appropriate bushing.

A "full length" die has no bushing, in the nomenclature I am accustomed to. A bushing die cannot size the neck/shoulder junction properly, since there must be a gap between the bottom of the bushing and the top of the body die (which is really what it is - a body die with a neck bushing added.)

 

[Brians356]

And they dont blow out as far on forming. 6br was the only brass that changed all other calibers are exactly the same

Here's what Kevin Thomas (Lapua USA) wrote about 6mm BR brass in 2012:

There ARE NO differences. There was a minor adjustment to the neck wall thickness (but no change to the dimensional specs used before or after) to get the cases to run a bit closer to the middle of the specs, rather than the high end, where we'd been running them previously. This amounted to less that .001" total, or about .0003"-.0004" per side.

That this adjustment coincided with the introduction of the new blue plastic boxes was exactly that; pure coincidence. As a result, you'll find earlier and later runs of 6mm BR brass in both types of boxes. Again, the box means absolutely nothing in terms of when the brass was run. Measure the brass, and size or turn as appropriate for your chamber/neck dimensions.


Kevin Thomas
Lapua USA

http://forum.accurateshooter.com/threads/gold-box-blue-box.3786701/

 

[Dusty Stevens]

Those boxes threw the earths axis off. 6br brass was all that changed but now you see cardboard boxes of any caliber fetching a premium because of it and a lot of dasher reamers not working well anymore