" how fast you can push a 308 175gr to 180gr SMK or A-MAX bullet ? What I'm hoping to get is 2,700 fps or more is that do-able ? "
The only way to know if 'your' rifle can and will get to the velocities you are looking for is to start loading. Start at a safe level and work up (slowly), looking for any and all signs of pressure. I don't see any reason you couldn't get close.
If you must, in your mind or your needs, surpass what is safe in your rifle. Look for a trade to a .300 Win Mag (in the same rifle) or some other chambering in other weapons.