308 brass necked down to 243?

Discussion in 'Reloading' started by tnshooter111, Oct 11, 2010.

  1. tnshooter111

    tnshooter111 Well-Known Member

    Jun 18, 2010
    I have been using LC brass in my 308 a lot the last few months because I got some at a good price. I also shoot LC brass in my 223 and like it a lot better than winchester or Remington brass. I was wondering if its worth the effort to neck this brass down to 243 win. I have ran some 308 brass through my 243 dies and they come out looking good but is there any addition steps that are required before shooting it in my 243?
  2. Kevin Thomas

    Kevin Thomas Well-Known Member

    Feb 16, 2009
    You can certainly neck the 7.62 brass down to 243, and have done quite a bit of this myself. While in the army, I had a virtually unlimited supply of LC Match brass, and a very limited budget, so this was what I fed my own 243 back then. There are some things to watch out for, however. One is neck thickness and clearance of the loaded rounds within the chamber. You will likely need to either inside ream or outside neck turn the reformed cases to ensure that you have sufficient clearance. The other consideration is the case thickness, and the need to revise the loads over what you'll seee printed in manuals. Military 30-06 and 7.62mm brass is generally thicker than their civilian counterparts, so you'll need to reduce the loads a bit below what the manuals will recommend. Oddly enough, this isn't the case with 5.56mm/223 Remington brass, and military stuff is virtually no different than most civilian makes, at least in terms of capacity.

    This is a pretty severe necking down and you'll be moving quite a bit of metal in the process. Some degree of work hardening is inevitable here, so I'd also recommend annealing as a final step (at least), or possibly an intermediate step if you're using an intermediate die, such as a 7-08, 260, etc..

    That said, I did this due to some pretty severe financial times back then (military pay being what it was/is), and was pinching pennies pretty hard. Today, I still reform cases for wildcats and some otherwise impossible to obtain obsolete cartridges, but that's about all. It's a pain, and there's too many good commercial 243 cases available on the market to mess with this particular conversion, at least in my opinion.

    Hope this helps,

    Kevin Thomas
    Lapua USA