It kills cleanly, it delivers its energy better, a larger sectional density(calibre) delivers the energy more efficiently, to get a smaller sectional density(calibre) bullet to deliver as efficiently the bullet has to by very frangible and this makes for a damaged carcase, i have had a helova job getting a roe that was hit on the scapula and only had fragments reaching the vitals, this was when we were trying to deliver minimum damage carcases to the dealer, for a better price, we tried that route and qwickly abandoned it.
Sika have loose skin and seem to have a layer of fat under it, when hit with the smaller calibres thay dont leave a very good trail, the skin seems to pull up or tighten and the holes dont line uo so well and its like the entry/exit are covered, i havnt had that problem thith the 308.
I suppose an example would be a knitting needle and a candle the needle hits less resistance and creates a smaller wound chanel, (larger wound chanel = greater blood loss, quicker death) whearas candel strikes larger area has greater resistance and dumps more energy into target.
Variety of bullets, the weight range and variety availible all over the world for the 308 is mind boggling, you can get anything to suite your quarrie.
Dry Powder.
Barry