Yep. That'what tells you tube has to be thicker. Seeing as how they are the same 30mm outside diameter, they would have the same amount of internal adjustment if everything inside were the same.
I use a Mk 4 16x40 and I will tell you for 600yd prone matches there is nothing I like better. Tracks perfectly, and is a good combination of FOV, eye relief, power, and lack of parallax. It is also one [beeep] for stout scope. 140moa elev. is pretty nice too. The only other scope I regularly use @ longer ranges is a Weaver T-36. Best target scope out there for the money IMO. They are known to track well, and do. I don't care much for the adj. dials or the 1/8 clicks, but when I want higher power, that is what I turn to. Once you get used to using M1's a lot, everything else sucks IMO.
I have always been satisfied with Leupold overall for a lot of reasons. Have had over 30 of them. I find them to be worth their asking price. Rugged, reliable, and easy to get fixed without a bunch of hassles. I'll leave the Euro crap for somebody else to over spend on.....