I have a winchester rocky mountain elk model 70 in 30-06. Im wanting to build a super accurate hunting rifle. Already has a timney trigger but needs a stock and barrell. Any suggestions? What caliber? Leaning towards the .270 or keep it a 30-06.

really depends on what you're shooting at, lothar walther makes som out standing barrels, as does shillen and hart. the stok optins for the model 70 are not as varried as the rem 700. i suggest looking at richards microfits for a good wood stock.

Why do you think 30-06 isnt accurate? Marine snipers in vietnam made kill shots out to 800yards. Why is the 300 mag so much better?

Yes, snipers did use it. they studied the ballistics as they do and found after 6 to 8 hundred yards the 06 groups opens up to double the size of 308 plus a 308 can be had with a short barrel. plus the 06 has a greater recoil. honestly if you want to shoot deer and yotes, I would say a 7mm 08, a 308 case necked down, great ballistics, and not under kill for deer, or super over kill on a yote. well it is a little over kill on a yote. but it is hard to find a round that is perfect for a 35 to 220 pound animal so. a 300 mag is a beast yes, lots of kick but a 30 06 and 270 are up there also, 7mm 08 has wy less recoil. a 243 would be an option also, same case as a 308 but a 6mm bullet, 55gr to 100 gr.  a very accurate round also. love mine!