What's More Powerful a .308 or .30-06

.45-70 ? As a straight-walled cartridge, it and similar types of ammunition are favored for deer in states were bottlenecked cartridges, such as 30–06, cannot be legally used. In its original loading, it delivers 2,221 joules of energy but has been loaded much hotter to the point that 3800–4600 joules are possible. 

A standard .308 load delivers around 3600 joules and 30–06 around 3800.

It is a good example of  “knockdown power" type of ammunition in that a large chunk of lead, traditionally not moving as fast, hits hard because of its mass. More modern cartridges made use of smaller bullets and smokeless powder to create ammunition that hits hard with a moderate projectile and much higher velocity.

The tradeoff is that .308 and .30–06 have far less muzzle drop at long ranges. Off the top of my head, the projectile drops something like 4′ at 400 yards, but it has been a while since I looked that up. .308 is much flatter shooting. Just my opinion. What do you think?