if you were going to bench shoot, which would you buy?

6mm for me. Mine punches .5in groups at 200yds all day

6mm! For what ever reason all the 6mm's I have owned have been more accurate than any 243 I have owned with the exception of only one that I had.

Acctually it would be a 6mm AI just for the simple fact that I hate trimming brass, that being said most 6mm/.243 chamberings are known to eat barrels. If you don't push it real hard its a greeat round either way you better reload cause there are little offerings for match grade ammo in either chambering.

I think you would have to have one built or buy used. I looked earlier this year for one and could not find a manufacturer that still makes one.

6mm/284!

If you are really serious about bench shooting then yes a 6mmPPC is what you want.

6mm rem. for sure

I have both and the 6mm is more accurate. It is also more picky. I have to load it so the bullets barely fit in the magazine. The closer to the lands the better. It doesn't shoot Remington cor locs worth a crap and I haven't found many factory loads it does. Hand loads will shoot under 1/2" at 100 though. If I were buying for hunting it would be the .243.

If buying it just for Benchrest, 6mmPPC or 6mmBR. If buying to hunt with also then 6mm Remington, like Dee said get the AI and life will be easier with less trimming and extended case life.

I am a 243 type guy so the answer to your question and only
pertaining to your question, 6mm Remington.

Handload..6mm.....OTC ammo..243