CDS offers easier or softer clicks, lower profile,and some what smaller numbers,and only 1 revolution if a zero stops used!
Target turrets come capped, M1's are not covered!
Factory M1's are not available with a zero stop but recently an aftermarket ZS is being offered, M1's are designed to use all the elevation in the scope, M1's are taller and offer very positive clicks!
I prefer my M1's to my cds but they both pretty much do the same thing out to 700 yds give or take!
