[DPB]

We have a better chance of seeing $1 a gallon gasoline again than we have of seeing the Army adopt the 6.8.

Also, I would buy new mags instead of doing anything that required me to manually change the profile of the feed lips. That's just long series of headaches and profanity waiting to happen.

The 6.8, 6.5, (and I believe) .260 all fit into the "standard" AR platform. The .243 is based on the .308, and will not, to the best of my knowledge, fit in the standard reciever size. Those of you who have seen .308 size ARs know there is a substantial difference in size and weight.

Ballistically, the 6.8 was designed to be accurate to 600m, highly destructive in soft tissue, and be optimized out of a 16" barrel (yes, I have a source for this but he wouldn't appreciate me using his name.)

The 6.5 Grendel was designed as a longer range target round, and will outperform the 6.8 at distances greater than 600m.

I can't really speak for the .260, but a lot of the "out west" 3 gun guys are shooting them.

Like tomcat said, do the research before you spend the cash.