Why not make the Sniper Rifle .338 Lupua then instead of the .50 BMG that way you have a difference between The Anti-Material Rifle... .338 Lupua is the real Sniper cartridge
Well, the .338 Lapua is a fairly new round. If you include that, you might as well include things like the 5.7x28mm. Also it may have simply been a desire to limit the number of different types of ammo.
I'm not sure what your specific complaint about the .308 round is, there are large variety of sniper and marksman rifles chambered in .308/7.62mm NATO. It's not at all foreign to the role. The Soviets also have the 7.62x54mm, which is ballistically extremely similar, and worked out great for their Mosin-Nagant snipers and then the SVD.
.30-06 is a much better choice than the .308. The .30-06 Rem. beats the .308 Win. hands down as it has a flatter trajectory, higher muzzle velocity, higher long range energy i.e. knockdown power
Er, no, it really isn't. The .30-06 has a
small advantage in muzzle energy due to having a higher velocity. But both rounds typically use about the same bullet (.308 inch diameter, 160-170 grains), and the .308 is measurably lighter due to its smaller case.
I use both the .223 Remington and the 5.56 NATO (which you can buy wholesale) cartridges in my Ruger M-14 Ranch Rifle the only difference I see is the price and a slight increase in muzzle velocity
I'm not sure if 5.56mm NATO even makes use of its higher pressure, in typical loadings. But it
could. 5.56mm is specced at 62,000 PSI, while .223 is only specced at 55,000 PSI. Higher allowable pressure equals more propellant equals faster or heavier bullet equals more power. Maybe we in reality don't use this potential, but it exists all the same. This validates the game's saying that .223 ammo has a 10% reduction in damage, in my opinion. It's not a completely inexplicable and left-field feature.
Edit: Haha, I see .46ACP/Gunny and I are fighting on the same team.