Welcome to LRH, and enjoy! As others noted, go with an action (you have plenty of custom actions to choose from) that will accommodate a 4" to take full advantage of the long, heavy, high BC bullets.I want to build a 300 RUM, what action would be best, I am think Rem Action. I'm also considering a heavy barrel. Any feedback is welcome
Bingo.The 700 action works just fine as stated. By the time you true the action, cut it for a 4" box, and put in a PTG bolt, you are really close to the cost of a defiance classic that is ready to go. You can sell the factory 700 bolt and recoup some cash but in the end you still have a rem 700.
Go full custom