Which caliber,270,308 or 30-06

Question
Mr.Zukowski,
I have been researching the 270,308 and 30-06 to try and determine which to buy and I am needing some help/ opinoins.I want to be able to shoot 300-500 yards with great accuracy weather its shooting at targets with my children as a hobby or hunting whitetail / muledeer.I know snipers use the (7.62x51) or 308 but when I compare the ballistics of this round to the 270 and 30-06 I don't understand. I want good accuracy and good knock down power 300-500 yards out. Using these 3 calibers can you give me your opinion which one would be the overall best?Thanks for your time.Garrett

Answer
30-06 has the widest possible application and still biggest selling caliber.
Loads from 55 grains to 220 grain bullets.
.308 Win. was designed be close to 30-06 but stack neatly in a box magazine.
270 Win is 30-06 necked down to 270.
Personally I would choose 30-06.
I can hit a 600 yard target with iron sites using M1903a3 or M1 Garand rifle.