Neck angles, headspacing, pressure generated by the cartridge when fired.
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.
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.
.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.
GTFO
30 caliber = .308 of an inch = 7.62mm
Yes. Significantly.
Yes it is, it uses a .30 caliber bullet which makes it a 30 caliber
No
308 calibre