Ian,...I noticed the same thing when looking through the Leupold catalog reguarding the part numbers for the 2 piece bases being the same. When I called, they told me that they had stopped doing that due to the Weatherby action stepping down an additional .020". Therefore, I deduced that if I were to use a 20MOA base set for a remington,..I would end up with a straight 0 degree and be right back where I started from. I am guessing that is right. I saw the Nightforce site listed them specificaly for the MK V action, so I will be attempting to contact them today for an explanation of the difference between the MK V and the 700 mounts. I'll post any asnwers that I get, so that anyone who ever needs to know will have a definitive answer.