Resizing 308 Win brass to 7mm08

Cleftwynd

Cleftwynd

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I am quite low on 7mm08 brass but have about 260 once fired 308 win brass that I can resize, the question is will the brass be exactly the same as the factory 7mm08? or is there some trick to making it uniform with the factory 7mm08 brass?

I figured instead of spending more on brass I would just resize the 08 stuff... should I just stuff it through my 7mm08 FL sizing die and not worry about it?
 
You may have capacity differences to factory 08 cases so for best accuracy you may want to develop a load specific to them. The capacity should be very close though since the cases are so close in size already. Since the case length is almost the same I don't see neck turning to be required. You may also need to anneal the necks to get them to form properly but not necessarily.

Main worry would probably be someone chambering them in a .308 rifle after reading the head stamps. All my converted brass (mostly .30-06 to 8mm Mauser) I put in boxes with specific labels stating they have been converted. Isn't fool proof but it works for my purposes. Since 7mm would just bounce down a .308 barrel it isn't too much of a risk to the user anyway (though I don't know if it would damage the rifle.)

Personally I would just run them through a FL sizing die, load with favourite 7mm-08 data, and label the box well.
 
I have a few wildcats that I size from "parent" brass and haven't had an issue yet, but I also don't share my reloads at all. Thanks for the heads up!
 
I size .308 Lapua brass to 7-08 to get nice brass.

FL size with good lube, then fireform without projectile, collet neck size after that, then a final annealing.

2.025" trim length on 7-08 vs 2.005" for .308

Your new brass will be short and will take time to lengthen, don't worry , this won't create any issues.If you use a FL or bushing neck die it will stretch faster.I use my collet neck sizer and haven't trimmed yet, some cases on 4th firing.

Depends how much neck tension you want and how fussy you are, you may want to turn the necks as well.

You may need to adjust your charge.
 
I bushing neck size, and am quite fussy, usually turn the necks... I also size with imperial sizing wax, or with caselube 2... usually the wax though
 
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