308 or 260 sized to 7-08

[sikwhiskey]

Looking at buying Lapua Brass for new M-70 in 7-08, wondering if I should buy 308 and size down or 260 rem and size up? I can turn the necks if necessary and anneal.
I have tried 308 to 7-08 with rem brass, after Full sizing, the brass chambered with a slight feel and I noticed a slight "donut" on the bottom of the neck where the die appears to have not reached. The Lee die was touching the shell holder + 1/4 turn. Kind of leaning towards the 260 brass to avoid this but have never tried it, will it thin the brass to much or not matter? Thoughts?

 

[iceman2]

The donut might be the displaced brass, you are making them smaller so the brass has to go somewhere. 260 brass may be the way to go. I have never tried that so if you could find a couple and try it might be the best way to find out without having to buy a bunch. Just my .02

 

[Kelly Timoffee]

I have done exactly what you are wanting to do.Going from .308 to 7-08.

I figured it is better to go thicker and turn than thinner and have issues with the necks.

I FL sized the Lapua brass but backed the die off just slightly, just enough to size the neck, THEN ran it through my 7-08 collet neck sizer(this step isn't necessary, just the process I used).

After that , I fire formed without projectile using cream of wheat method.

Have only neck sized after that point.

The brass will be short , but that is a non-issue , I think it winds up being .010" less but being quality brass all was well.

 

[c-fbmi]

Go 308 down and just full length size in a 7-08 die and work up loads, don't worry about the donut, it'll iron out with the first firing. You shouldn't have to worry about neck thickness either unless it's a min cut match chamber. I make everything from 243, 260, 7-08 and 358 with 308 brass. Had to buy 2 boxes of 260 and pull and reload them when I took my boy to Africa as none of the 200 rounds he had actually had a 260 headstamp and SA can be funny about that.

 

[wilbar]

Thanks for the refresher. I've been considering better quality brass for a while and haven't found 7-08 in stock. Just saw a decent deal on Lapua 308. I might go for it now.

Willy

 

[sikwhiskey]

Thanks, Ordered the 308 lapua brass. The donnut on the rem brass did Iron out after the first firing, with 38 grns of Blc-2, Fed 215m primer and 140 grn bullet. looking forward to using Lapua.
This is my wife's rifle, so I won't use BLC-2 or ball powder for reduced loads, will try mag primers and Varget when the brass arrives, as I have plenty.