They both shoot the same diameter bullet(.308),However a 30-06 has a larger case capacity(The amount of powder it can hold)which means when loaded up to its specs,can push heavier and faster than a .308win.A 30-06 is about the fastest .30 caliper cartridge that you can get without steping up to a Belted Magnum Round.The 308win/7.62x51 Nato is the result of simply pushing back the shoulders of a 30-06sprg case and trimming.That cartridge was desighned during the time the U.S. Military was trying to phase out the 30-06,because then soldiers could carry more ammunition with less weight.However by doing so they did loose on accuracy past the 500 yard mark because of its slower velocity.The original Springfield model of 1903 chambered in 30-06(Formerly known as the 30-03)was accurate out to 640yards pushing a 180gr bullet,far beyond what the .308 win can do even with a 148gr bullet...
it is 3006 cal.
Whether you need a 5.56 or a 308 depends what you intend to shoot. A .308 is intended for larger game like deer and elk.
I'm not quite sure about the 3006, but I know that the longest recorded kill shot with a .308 was at about one and a half miles, possibly more.
.308
it might be for the Krag rifle, cal. 30/40..... not 30/06
100-300
The .50 caliber is larger in diameter than the .308. If you are referring to the bullets for the .50 BMG and the .308 Winchester, the .50 is MUCH heavier, and much longer than the .308.
It uses a 30 caliber or .308 inch diamiter projectile. .308
Negative, 308 is a 30 caliber bullet and 30 doesn't fit into 25.
a "308" measures .308 inches while most 30 caliber ammo measures .312 inches. Strange as it may seem both are classifies as 30 caliber ammo.
Given the limited information in your question I can only give a general reply. The caliber is the diameter of the rifle groove to groove in thousands of inches. So the difference would be .450" - .308" which equals .142". There are a lot of specified rounds of ammunition that use .308 and .450 bullets. In general the larger caliber bullet would also be more powerful.
30 caliber = .308 of an inch = 7.62mm