308 brass to 243

[rembolt]

Hi guys being a little short on 243 brass i thought i might run some of the 308 brass i have through my 243 FL die.is there any thing i should do to the brass after i do this.ie fire form ,anneal ,etc .any advice welcome.

 

[Canuck223]

You may have to turn the necks, as I believe cases tend to thicken as the caliber is reduced.

I'm not sure if the old timers wouldn't suggest a step or two along the way from .30 to .243

 

[762nato]

definitley have to ream the necks, I would anneal before doing and go in a couple of steps. Would be a lot easier to buy .243 brass...

Andy

 

[rembolt]

thanks for the replys guys.i have a fair amount of 308 brass i thought it might save me sum cash .but seeing i don,t have any dies between 30 cal and 24cal or a neck turning tool .i would say your right it would be easier to just buy more once fired 243.thanks again rembolt.

 

[.308--win]

I just recently necked down some 308 for my 243, I ran them through my 7-08 die first then through the 243. Didn't need to trim them, loaded them and they shoot just like my bought 243 brass!

Perry

 

[Levi Garrett]

I went from 308 to 243 in one go, their fine in factory chambers. Only difference is, they come up short, not by much, so they will stretch nice with lots of brass there.

 

[rembolt]

Thanks Levi I think I will try a half dozen just to see what kind of results I get . do you load them light for the first fireing . I will be firing them in a 700 rem thank again.

 

[shootist22-250]

I went from 308 to 243 in one go, their fine in factory chambers. Only difference is, they come up short, not by much, so they will stretch nice with lots of brass there.

Yep, I have done literally hundreds this way.

The problem I encountered was that the neck outside diameter was too large for the Ron Smith chambered barrel. Nothing that an outside neck turner couldn't fix.
Perhaps the problem could have been with the RCBS full length die being used to down size the case.

 

[Al-Sway]

I have also done this, and I also do it in one step. A few suggestions:
- full length size them in .308 dies first
- take the decapping pin out of the .243 die and then full length size them all in the .243 die.
- expand the neck. Now, try a case in your rifle to see if it closes easily. Then, make a dummy cartridge and try it again to see if there is any difference. IF the loaded round is harder to chamber than the case, you will need to outside neck turn or ream the neck. If there is no difference, you probably have enough clearance with your lot of brass, and your rifle.
Now that you have it full length sized and neck expanded, now anneal the case necks.

 

[shootist22-250]

I have also done this, and I also do it in one step. A few suggestions:
- full length size them in .308 dies first
- take the decapping pin out of the .243 die and then full length size them all in the .243 die.
- expand the neck. Now, try a case in your rifle to see if it closes easily. Then, make a dummy cartridge and try it again to see if there is any difference. IF the loaded round is harder to chamber than the case, you will need to outside neck turn or ream the neck. If there is no difference, you probably have enough clearance with your lot of brass, and your rifle.
Now that you have it full length sized and neck expande, now anneal the case necks.

Good thought!!
However, in my case there never has been a problem with necks cracking.
All my case problems, so far, have been with head separation.