Hey, i apologise if i am interrupting, but are you talking about my scope?Completely agree in most cases, but his scope has only 60MOA total vertical adjustment to begin with.
Assuming zeroing near middle to just above center, he is going to be REEEALLLY close to the top of the travel when zeroed. And if his mount is off left to right, the erector may hit the side walls well before he gets to zero. So in this case, without changing scopes it MIGHT need a different base to allow zeroing the scope at 40-50yds.
Had a similar issue with a Nikon Buckmaster on my 17HMR and a 20MOA base: it literally just zeros at 100 with about 5 moa to spare but I cannot dial left more than 3 moa from zero without bumping the wall of scope body. Problem disappears at 150-175 because I gain more room as tube gets wider.