Well...one has to define the parameters for what max point blank range means to them for their load and intended target size which will then determine the zero point to achieve MPR which will vary. It isn't static.
8" target size, punch that in to a ballistics computer like JBM along with your load and weather data and it will spit the answer out. http://www.jbmballistics.com/
Some people may want more precision than a point blank type zero allows and opt to zero at 100yds and know their holdovers at other ranges.
With my TA33 ACOG zero'd 1.5" high at 100yds with 75g ammo, I was able to get 2nd round hits at 500yds, then switching to 55g ammo, again I needed the first shot to adjust and get 2nd round hit. This was on a range at 7000ft elevation, hot weather, shooting uphill with 5-7mph wind at a 20" and 12" gong. So, I was aiming at about the 450m mark with 75g ammo to hit at 500yds in those conditions and aiming at a hair over the 400m mark to hit with the 55g ammo. This all made sense as the BDC was for 62g at sea level at 500m. The high elevation, hot weather, yds vs meters and up angle all make for less drop than 500 meters in standard conditions.
To get a guaranteed 1st round hit at that range, I'd need a range finder, ballistics chart, and a scope I can dial exact adjustments on.
