Jeff.. I would not be surprised if you that rifle can not get to around the 2950-2970fps crammed with RE-15.
There is enough freebore to get a good 31.5grains of powder in there!
Have a nice custom die made up for the chambering, and the brass should last real well also!
The yellow boxed 108's...... depending on the price they maybe the new way I might go also, well give a try. The 107MK's are real good though, and hard to go past!