Originally Posted by calebjay
It could be like that for sniper rifles too one is more powerful
The higher the grain (weight) of the bullet, generally the more powerful, so yes a 800 grain 50 bmg will be more powerful than a 647 grain 50 bmg. It also depends on the length and how 'hot' the cartridge is loaded.
It is possible for a smaller cartridge to be more powerful depending on many variables.
Rifles themselves are only designed to propel a round. if you were to have a Barrett M95 chambered in .22lr and a hunting rifle in 338 Lapua, obviously the 338 would be more powerful.