Rool Of Fumb Feory 4 .177in cal PCP Rifle.
Point Blank Zero for a sniper type powder burner is 350yds + allowance for bullet drop at proposed total range to target this obviously will be a variable.
Point blank zero for a serious sub 12ftlbs Air gun is 35yds, Coincidence???
Set rifle at 35yds then check at 10 yds, correct any crossover,
note pellet drop at 10yds
This gives very close to the same aim point from 10 to 35yds,
40yds horizontal reticule aligned at top of target area
50yds 1 mil dot elevation aligned top of target area
6yds 1 mil dot elevation aligned middle of target area
This will get you through the early days, untill you can digest and utilise the superb info on this thread