I would say that the .223 Rem. is probably grossly over rated
At this year's Nationals, the US Army team set a team record for service rifles at 1000 yards using AR10's and 185-gr. Berger bullets in their 20 inch barrels. Betcha a bag of goodies their handloads were up the the blue pill pressure range to get enough muzzle velocity to keep that bullet supersonic through the paper 1000 yards down range. 'Course all the service teams have a long track record of loading match ammo way, way over SAAMI and MIL-SPEC levels for the cartridge used.
If anything is underrated, it's 6.5x55 Swede
If anything is underrated, it's 6.5x55 Swede. Americans have scoffed at this cartridge for decades. Hell, we still can't come to terms with it. We have to go off and have a "sister" cartridge to it...the .260Rem.