Filaman,
One of my two other drillings is another, but slightly heavier, Sauer in 6.5x57R (the shotgun barrels are, of course, 16-gauge). The rifling twist is 1-8, and even with the slightly lower-pressure loads used in drillings, it duplicates the factory ballistics of the 6.5 Creedmoor.
It's also very accurate for a drilling. In fact, the guy I bought it from (luv2safari here on the Campfire) stated it was the most accurate drilling he's ever owned. With a 4x scope it will put five in an inch or less at 100 yards with all the bullets tried so far, which include the 129-grain Hornady Interlock, 129 Nosler AccuBond Long Range, and 125 Nosler Partition.
