I'm having the chamber end of one of my 308's lopped off and rechambered/refitted using a tighter than SAAMI dimension match reamer. It won't require neck turning, but it will still be a lot closer to cartridge/bullet dimensions in the chamber neck and throat. Even a SAAMI minimum reamer is pretty loose for the 308.
Have you considered a Palma chamber? Short throat will allow you to reach the lands with just about anything.
John
If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then I will hear from heaven, and I will forgive their sin and will heal their land. 2 Chronicles 7:14
