I was taught in the military to zero at 25 yards for hits out to 250 yards. But there are different strokes for different folks. But all in all a good video.
I was taught the same with the M14 using standard ball rounds.What happens is that at 25 yds, the trajectory goes from below the sight line to above it, it continues above it until 250 yrds where it falls below the sight line again.Under 25 yds, you will soot very slightly low, between 25 and 250, you will shooting high and past 250 yds, you will be shooting low again.
To follow up on FQ's theme, what's the deal with French Toast ?