I think sometimes we are " picking nits" on these threads. Truth of the matter is for 90% of the hunting any American hunter will do on this continent....it doesn' t make a squat of difference if you stick a 150grain .277 caliber bullet through the lungs, a 180 grain .308 caliber bullet through the lungs, or a 210 grain .338 bullet through the lungs. (Or for that matter you fill in the weight and caliber!)
If the velocity is sufficient for you to accurately place " said bullet" through " said lungs" and comparable expansion between " said bullets" occur.....the animal will expire without too much fuss. And in the final analysis any thing more than that...is just that, superfulous.
Hey it the american way. The speed limit is 70mph and every automobile will reach that speed so why do we need 200mph Ferrari' s and such? Because we want them, do we need them ? Nope. A Corvette is one awsome machine but A ferrari is a little better, and a Lamborghini is even better. Get my point.
If one rifle has just a little more velocity, is a little more flatt shooting , has little more energy, well we want it. Do we need it prolly not, we just want the best, hey it' s in our nature. God bless america.