making 308 from 243 brass

dudley2112

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just wondering what would be involved in necking up 243 to 308, would it just be a matter of lubing it up well and running it into a 308 sizing die then cutting to length?

thanks
 
there's .030 diff in length, the .243 being longer. I would de-cap them using a full length re-sizer, should not be a problem. Yes, use lube on the inside of the case, especially. Then trim to length and away you go. Good luck. Most people are going the other way.
 
Yes, most are going the other way... but, if you insist...

If it's been fired, you may want to anneal the case necks.

Personally, I would get a spare .308 decapping pin/sizing button and chuck it in a drill; grind a V-taper on the button so it looks like a gently tapered "carrot". Smooth and polish the button (being sure not to change the critical dimension of .308!) and there's your necking-up expander.

I recommend the drill because grinding while spinning simulates a toolpost grinder (i.e. will give you an even grind without much effort). Spin the button as fast as you can in a drill when grinding against a wheel or belt sander - PARALLEL to the long axis.

-M
 
thanks :D ya iknow most people are going the other way but i picked up some once fired 243 winchester brass at the range and i have a buddy that wants 308 brass so i figured why not try it
 
Oh, and one more thing...

IMPERIAL SIZING DIE WAX IS YOUR FRIEND.

Use it early and OFTEN on the sizing ball. Screw the decapper/button all the way down so you can just reach it with your fingers and put sizing wax on it every 3-4 cases.

-M
 
I have my suspicions that trying to run a .243 over the .308 expander button would not work well. A tapered expander would be a good idea.
By the same token, just because something can be done, doesn't necessarily mean it is worth doing.
 
well we did it today just used lee resizing lube and the only thing i had to make sure to do was put a big glob in the case mouth other then that they all necked up without any problem what so ever, necks werent really all that much thinner either,
 
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