Had to add my 2 cents here.
I have both a 6.5 prc and a 6 prc.
I use Lapua brass for the 6.5 prc and ADG for the 6 prc - mostly to keep them separate, since there isn't 6 prc head stamped brass available.
The lapua brass is definitely harder (if that's the correct word?) between the 2 - in case prep you can feel chamfering, priming, etc. takes more physical effort on the lapua brass. Does that mean the lapua will last longer? Probably - but both will shoot extremely well.
*1 thing that irks me with Lapua is they don't ship you brass in reusable containers - like ADG does with nice, reusable ammo boxes. It's not a deal breaker by any means, but I don't love that Lapua brass inevitably has some dinged necks and bodies from shipping.
A good rule of thumb is to use Lapua if they make it for your caliber, if not, I typically go to ADG.
Either will work great! Best of luck to you
