I've got a new 550 action (standard size, 30-06 bolt face) and am wondering if the barrel threads are the same as the large ring mausers? What exactly is the dimensions of the threads?

Thanks.

The barrel threads are different. Large ring M98 threads are nominally 1.100" dia x 12 TPI with 55-degree Whitworth threads. The CZ threads are metric. The '06 action has M26x2 threads (approx. 1.024" diameter) and the Magnum action has M28x2 threads or approx 1.102" x 12.7 TPI with 60-degree threads.
Roger