Re: .308 Winchester and .30-06
ironwolfjoe, comparing cartridges from a ballistic chart is very misleading. For deer to elk size game and 300yds, just about any hunting cartridge will work. Just do the 45-70/ 22250 comparison. Which do you think will be more effective at dropping a moose? The 22-250 usually have more "print" energy at 200yds.
There are a varieties of thoughts on what works best. Some like heavy bullets at mod. speeds, others like the super zappers - high vel and light bullets. They both work if you put the bullet in the boiler room.
As to which is a better killer, I have compared notes with many hunters and you can read data in all hunting mag which clearly shows that there is no cut and dry "drop'em in their tracks" cartridge.
I have shot deer with the same '06 load that dropped and others that ran a bit. All were hit is the same general area and of varying size. The big ones dropped and the smaller ones ran off.
Is the '06 a weak cartridge? Nope. Just animals are unpredictable in how they will succumb.
Trajectory between the three is also moot. Just about any load will work within reasonable holdover out to 300yds. On this board we are concerned about going much further.
There are differences once you get past 400 to 500yds. Wind drift, retained vel/impact vel, bullet design become very important. At extended ranges, I lean towards the 270 because of the higher BC and SD bullets when the mid weight 30cal bullets (150 to 165gr).
I am now shooting a 6.5-06 with 140gr SST bullets and there is simply no comparison on impact energy with a '06 and 165gr SST at 500 and 600yds. The 6.5 is way higher. Although a lighter bullet, the BC is much higher then the 30's so slows down less. Impact vel and thus energy is higher and the high SD penetrates like there is no tomorrow.
The 270 would be similar when using 150gr SST or ballistic tips.
If you hunt in windy conditions, I would suggest you go with the 270 and 150gr poly tipped bullets. Launch them accurately at 2850 to 2950fps and it will do everything you want plus have the ability to shoot through windy conditions much better.