The Baikal uses a system of bolts to regulate. Regulation is made by sighting in the rifle then getting the shotgun barrel point of impact near dead center for the rifle. I suggest you pattern on full choke at 30 yards. I had them tuned in very well for shot loads to the .308 rifle load using the Express sights and a 1.5-4X long eye relief scope. Frankly I preferred the Baikal with open sights if I had a lot of bird hunting opportunities.