I'll bet he's talking .338 Lapua Magnum.
.308 / 7.62x51
- Cost per round: $0.83
2-REML308W4BX - Ammo .308 Winchester UMC Metal Case 150 Grain 2820 fps 20 Round Box
Muzzle energy: 2,648
The .308 would bring down any animal in N. America with a well placed shot under 600 yards (correct me if wrong)
The .338 Lapua Magnum is IMHO, overkill for anything in N. America and way over priced and completely impractical for anything but a single shot from 1,000 yards. That being said; If i were rich, I would love to have a bolt action rifle chambered just for that!
.338 Lapua Magnum
- Cost per round: $5.63
53158 - Ammo .338 Lapua Magnum Remington Rifle Cartridge 250 Grain Lapua Scenar 2960 fps 20 Round Box
Muzzle energy: 4863 (Nearly double the power of the .308, 3.7 times more powerful than the .223)
If going for overkill, I would go with the 50 BMG, as ammo is cheaper, will fly further and do more damage.
$3.50 / round
muzzle energy: 12,883 ft/lbs. (4 times the energy of a shotgun slug)
Too bad I can't have one in this golden state.