Nathan: yeah....I am glad that somebody noted the "caliber" vs. "cartridge" thing.
OP - There are lots of .308 caliber cartridges. The Hornady load manual lists 19 of them.
About the differences between the .308 Winchester and the .300 Winchester Magnum.....one commonly accepted idea is that the .308 Win is at its best with bullets of 180 grains or less.
The cartridge is one of two that are specified for Palma Match shooting, an event that is shot at 800, 900, and 1000 yards.
In Palma matches, the most common bullet used with the .308 Win is a bullet at 155 grains.
PS - the other Palma cartridge is the .223 Remington. Metallic sights only.
"Only hunting and mountain climbing are sports. The rest are just games." - R.Ruark
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