Thread: .308 into .243?

In common calibers it's technically possible, but as others have said unless you are badly short it's not worth it... Also consider the issue of mismatched head stamp, while it's unlikely to get an issue with remaking .308 into .243 in terms of chambering it is a possibility that you may strike issues with picking up a random .308 case and ending up with it stuck in a die or other whoopsies.

I saw a guy with a box of Win .308 ammo half of which was stamped 7mm08. He just hadn't checked and picked up 20 cases off the range and went home to roll up 20 more and never realized the difference.