Originally Posted by mrbigtexan
whats the pros and cons of each? which one has more energy at 1000 yds? what about recoil, which one has more? whats the trajectory like shooting a 140 gr. bullet out of each? and which one would you recommend? compare them to 243 and 308, i have one of each. thanks for all your input.
I am of the opinion that you cannot outperform a given cartridge by necking it down and putting a smaller bullet in it. That said, If you shoot equal grain bullets of similar form design, the smaller caliber will win due to increased sectional density and subsequent higher BC. Now max potential of each, the larger of the two will typically have the favor. At least for energy down range/less windage.
An example would be the 260/140 AMAX versus the 708/162 AMAX. The 162 is going to kick the crap out of the 140. More downrange energy, less drift, and a bigger hole to boot.
Some may say that the 260/140 will be much faster. A little faster maybe. The fact is that equal barrel lengths in each caliber with equal cases and equal bullet weights guess which one is faster. The one with the bigger bore. The 708/162 versus the 260/140 velocities will be closer than you would think on the surface.
You can apply the same principals to the 708/162 versus the 308/208. In this case though, the 208 is conciderably slower than the 708/162 but will hit with a lot more energy. Windage will favor the 162.
Other factors to concider is that the one with the larger bore will have better barrel life but more recoil.
Pick yur poison and be happy.