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The 25-Yard Zero and What It Really Means at 100

"Zero at 25 and you're on at 100" is one of the oldest lines at the range, and it's close enough to true to keep getting repeated — and wrong enough to cost people a deer. Here's what actually happens between 25 and 100 yards, and how to use the 25-yard line the smart way.

Dead-on at 25 means high at 100

Your scope sits above the bore — around 1.5 inches on a typical bolt rifle, around 2.5 inches on an AR. The bullet starts below your line of sight and climbs toward it. If it closes that whole gap in only 25 yards, it's climbing at a steep angle — and it keeps climbing past the crossing.

By 100 yards that steep launch has the bullet well above your line of sight: roughly 2 to 3 inches high for many common hunting loads with a low-mounted scope, and more like 4 to 6 inches high with an AR-height optic. The exact number rides on your sight height and load, but the direction never changes: a true 25-yard zero prints high at 100, every time.

Three inches high is the difference between a centered hold and clipping the top of a target — or missing over a coyote's back. If you zeroed at 25, packed up, and hunted, you never had the zero you thought you did.

Where the old saying comes from

The rule survives because 25 yards does put you on paper at 100, and because the steep crossing buys a far zero somewhere well downrange — with many carbine loads, dead-on at 25 lands you in the same general territory as the 36-yard zero, with a far crossing a couple hundred yards or more out and a tall mid-range arc. Militaries have used short-range zeros as stand-ins for battlesight zeros for generations. That's a deliberate trade, not "on at 25 = on at 100."

The fix: print slightly low at 25

If what you want is a genuine 100-yard zero, the 25-yard line can still deliver it — you just aim center and put the group a little below the aim point, because at 25 a 100-yard-zeroed bullet is still climbing. As rough orientation: about three-quarters of an inch low for a typical bolt gun with a low scope, closer to an inch and a half for an AR-height optic. Your exact number depends on sight height and load.

This is proxy zeroing, and it's the same method as setting a 50-yard zero at a 25-yard range — that guide walks the logic in detail. The Zero Considerations proxy-zero mode computes your exact offset from your load and sight height (it can derive sight height from your optic and mount, so you're not guessing at that either).

The efficient 25-then-100 workflow

1. Print the free 1-inch grid target at 100% scale. Every square is exactly one inch, so offsets read straight off the paper.
2. At 25 yards, shoot a 3-round group. Photograph it with the app — the coded corner markers set true scale and correct camera tilt, the holes are found automatically, and you get the click count for your optic's click value.
3. Dial either to dead-center (if you're rough-ing in before moving back) or to your computed low offset (if 25 is all the distance you have).
4. Move to 100 if you can, shoot a confirmation group, photograph, and apply the final refinement clicks. Two or three groups total — not a box of ammo walking shots in.

Common questions

Is a deliberate 25-yard zero ever the right choice?

If you understand you're buying a tall mid-range arc and a far crossing well downrange, it's a legitimate carbine setup — that's battlesight thinking. For a hunting rifle you want centered at 100, it isn't; use the low-offset method instead.

Does this apply to red dots and pistols?

The geometry is identical; only the numbers shrink. A pistol dot sits under an inch over the bore, so the offsets are small — see the pistol red dot zeroing guide.

What about 50 instead of 25?

If your range has a 50-yard line, it's a gentler proxy for 100 — the offsets are smaller and errors multiply less. Same method, better leverage.

More zeroing guides

• The 36-yard zero for 5.56 carbines
• Setting a 50-yard zero at a 25-yard range
• Zeroing a pistol red dot: 10, 15, or 25 yards