Zeroing Guides
Which zero to use for each cartridge, with the full drop table for every option side by side. Pick your cartridge below.
AR-15 and intermediate cartridges
5.56x45mm NATO
AR-15 / AR-10, standard-height optic, 2.6" over bore
Bolt-action hunting rifles
.270 Winchester
Bolt action, standard scope rings, 1.5" over bore
.30-06 Springfield
Bolt action, standard scope rings, 1.5" over bore
.308 Winchester
Bolt action, standard scope rings, 1.5" over bore
6.5mm Creedmoor
Bolt action, standard scope rings, 1.5" over bore
Rimfire
Pistols and red dots
Key terms
- Near zero
- Where the bullet first climbs up through the line of sight. It starts below the sight, because the sight sits above the barrel.
- Far zero
- Where it falls back down through the line of sight. A "200-yard zero" is the far zero; the near zero comes with it.
- Max ordinate
- The highest the bullet gets above the line of sight, between the two crossings. This is what makes a zero shoot high in the middle.
- Point blank range (MPBR)
- The zero that keeps the whole arc inside a vital zone for the longest distance, so you can aim at the centre and hold dead-on.
The height of your sight over the bore decides most of these numbers: 2.6" on a flat-top AR-15, about 1.5" on a scoped bolt gun, under an inch on a pistol. Each guide is solved at its platform's height. To solve your own load, use the trajectory calculator.