Since it's a .342" neck with a shortened freebore, it'll probably be tightened from the .310" figure too.
I really like the rifle you've got there, and I bet you can even shrink that ten shot result when you get to tuning loads for it.
For pure accuracy potential evaluation purposes, try some IMR3031 under a 168 grain match bullet of some sort. It's old school, but it's shot very well in over a dozen 308's so far. In a Remington 40X I've managed a ten shot, half MOA group with the combination.
