Red Dot Zero Distance Chart: 25m vs 36 vs 50/200 Yard Zeros

For most AR-pattern rifles in .223/5.56, a 50 m or 50 yd zero is the best all-round red dot zero: the bullet stays within about 5 cm (2 in) of the dot out to roughly 200 m, so you aim at the middle and hit the middle. A 25 m zero is convenient on short British ranges but shoots 15–21 cm (6–8 in) high between 100 m and 200 m, and a 100 m zero never shoots high but drops quickly beyond it.

The charts below show how each common zero actually behaves, in metres and centimetres with the yard names kept, because "36 yard" and "50/200" are what these zeros are called. There is also a separate chart for .22 LR rimfire, which behaves completely differently.

Why zero distance matters

A red dot on an AR-15-pattern rifle sits well above the bore: about 2.65 in (67 mm) at absolute co-witness height, because the rail itself is about 1.24 in (31.5 mm) above the bore. The bullet leaves the muzzle below your line of sight, climbs up through it (the near zero), peaks, then falls back through it (the far zero). The distance you zero at decides where both crossings sit and how far the bullet strays from the dot in between.

5.56/.223 red dot zero chart

Figures are bullet impact relative to the dot, in centimetres (1 cm is about 0.39 in). Positive means high. Distances are in metres with yards in brackets.

How we calculated it: 62 gr bullet (SS109/M855 type) with a G7 ballistic coefficient of 0.151 at 2,950 fps (899 m/s), a typical 16 in barrel figure; sight height 2.65 in (67 mm); standard atmosphere; no wind. We used the open-source point-mass solver py-ballisticcalc and checked it against CCI's published .22 LR trajectory, which it reproduced to within 0.1 in. Your rifle, barrel length and ammunition will differ, so treat these as a guide and confirm on paper.

A faster load moves every far crossing outwards. Driving the same bullet at 3,050 fps (930 m/s), which a longer barrel can do, moves the 36 yd zero's far crossing to about 273 m (299 yd). That is where its reputation as a "300 yard" zero comes from.

The 50 yd and 50 m zeros are not the same

A British range is laid out in metres and an American zero is named in yards, so they are easy to confuse. The difference between 50 m and 50 yd is 4.3 m, and it moves the far crossing in the opposite direction to what many people assume. Zeroing at the longer 50 m brings the far crossing closer, from about 198 m to about 183 m, because the bullet is climbing less steeply when it reaches the line of sight.

That produces a handy coincidence: for typical 5.56 loads, a 50 m zero is also very close to a 200 yd zero. Either is a good choice. What matters is writing down which one you set.

Mount height changes the numbers

A taller mount means the sight sits further above the bore. With the same 50 m zero, it pushes the far crossing out and increases both the mid-range rise and the close-range drop.

The heights themselves are explained in the red dot mount height chart and the co-witness heights guide.

.22 LR rimfire red dot zero chart

A .22 LR travels at roughly a third of the speed of a 5.56, so the curve is far steeper. This chart uses CCI Standard Velocity (40 gr, 1,070 fps, G1 ballistic coefficient 0.120, as published by CCI) with the dot 2.6 in (66 mm) above the bore, roughly AR co-witness height. Measure your own rifle, because rimfire AR-pattern uppers vary.

The useful point: with this sight height, a 25 m zero and a 50 m zero are effectively the same zero. That suits the many British clubs that shoot rimfire at 25 m indoors and 50 m outdoors. For magnified rimfire setups, see our guide to the best scopes for a .22 LR rimfire.

Metric and imperial equivalents

Practical notes

• Only have 25 m? To approximate a 50 m zero with the 5.56 load above, set the group about 3 cm (1.2 in) low at 25 m, which is roughly 4 MOA at that distance, then confirm at 50 m when you can.
• Hold over up close. At 10 m the bullet strikes roughly 4–7 cm (1.5–2.8 in) below the dot depending on mount height. That matters on small targets such as a head-sized plate at a practical rifle match.
• Using a ranging reticle? The Holosun ARO EVO SPR reticle's holdover marks are calibrated by Holosun for M193 5.56 at 3,050 fps, so check its marks on paper with your own load.

For the step-by-step process, read how to mount and zero a red dot. Click values are explained in what is MOA? and the MOA at distance chart. A 2 MOA dot such as the SIG ROMEO5 Gen II covers about 6 cm at 100 m, which is well within the spread of the 50 m zero; our rifle dot sights range has 2 MOA dots and circle-dots in red, green and gold.

Frequently asked questions

What is the best zero for a red dot on an AR?

For most .223/5.56 shooters, 50 m or 50 yd. Both keep the bullet within about 5 cm of the dot to around 200 m, with no need to think about holdover at typical UK range distances.

Is a 50 m zero the same as a 50/200 zero?

Close to it. With typical 5.56 loads a 50 m zero crosses back at about 183 m, which is 200 yd. A 50 yd zero crosses back at roughly 200 m instead.

What distance should I zero a .22 LR red dot?

25 m or 50 m; with the sight at AR height they give almost the same result. Beyond about 60 m you will need to hold over.

Why is my 25 m zero so high at 100 m?

Because a 25 m near zero means the bullet is climbing steeply, and it peaks around 150–200 m at roughly 21 cm (8 in) above the dot with 5.56. Switch to a 50 m zero if you shoot beyond 50 m.