I can't see why a .300 Ackley with 230gr Berger Hybrids can't compete against a .338 Lapua at long range... Since the .300 Ackley is basically just the belted version of a .300 RUM (as far as case capacity and velocities go).
I'd love to see someone do an identical rifle match-up side by side with a .338 Lapua with Bergers and a .300 Ackley with 230 Bergers. I bet they'd be alot closer than you'd think.