New guy question 762 vs 308

[Jimmy's]

Unless you got the ammo for free why choose it over commercial or hand loaded.

[MolonLabe2008]

Will I be able to shoot 762 with my 308 JP supermatch barrel and young manufacturing BCG? It's my first AR build and have been getting mixed answers

http://how-i-did-it.org/762vs308/chamber.html