The scope in question has a 30mm tube but 1" lenses in it. They do this so you have more elevation ..windage adjustments at long range. You want a "real" 30mm scope then buy a S&B,Zeiss,Swaro,Kahles,Meopta,IOR and probably a few I forgotor even the highend Leupold VX-7. 30mm tubes are theoretically stronger but it would depend on the alloy used , manufacturing method to see a consistent difference.