Suprised no ones answered this, hell i'll have a go
I seem to remember a max of 12 mag but i stand to be corrected.
The viper fixed 10 is a very popular choice and was what i was using until i went to the mk 4. I found the scb ret to give an aimpoint for all ranges.
I used to zero at 30yds and parralax at 25, this gave a clear view from 12 ish out to 40, some use the slight blur to distinguish the 45's.
8yd'ers were a bitch tbh but not all courses set mini's on every peg
Bracketing is a dark art that i've never tried, you need to know the size of a standard knockdown with a kz in the center, around 110mm i think, from the spring to the center, this way once you've measured this at all ranges you make yourself a chart,...not all kz's are center so that's that idea pooped.
But beware of course setters making smaller versions so that you'll mis-range and shoot straight over the top
I'm sure some more knowlegable members will provide the correct info
atb, jay.