30.06 and .300WM are both Long Action calibers, so I wouldn't expect any differences.
The barrel and the receiver are both fully seated. I was using 180 grain Federal Ammo, so nothing exotic or a handloaded. And I did switch to the .300WM magazine (you are correct .300wm won't fit in the .308 mags.) Still, the bolt stops more than a quarter of an inch shy of the back of the groove on the receiver.
A member on another board suggested there was a short action adapter held in by the trigger group that must be removed. Any guidance or info on that?