Rimfire Optics & Sighting-In for Treetops

A squirrel sits dead still on a limb 18 yards up. You center the crosshair on its head, squeeze… and the shot prints an inch high. You didn’t flinch — your scope and zero were set for the wrong game. Treetop squirrel shooting has two quirks most shooters never think about: a near zero and close-range parallax. This lesson sorts both.

Quick recall

Quick recall from the .22 Rimfire lesson — why does precise aiming matter so much more with a rifle than a shotgun?

Quick recall from the .22 Rimfire lesson — why does precise aiming matter so much more with a rifle than a shotgun?

A rifle fires one bullet on one line — there's no forgiving pattern to cover an aiming error Because rifles recoil much harder Because a rifle is louder

Check answer

Use a rimfire scope, not a borrowed deer scope

A scope’s parallax — the distance at which the reticle and target image sit on exactly the same plane — is fixed when the scope is built (unless it’s adjustable). Centerfire/deer scopes are set for ~100 yards or more. Rimfire scopes are set for close range, often around 50 yards — right where squirrels live. Put a deer scope on a squirrel rifle and every close shot fights a parallax mismatch. The fix is simple: use a rimfire-specific scope (or one with adjustable parallax you can dial down).

What parallax does to a close shot

Parallax is only perfectly corrected at the one distance it’s set for. At very different distances, if your eye isn’t centered behind the scope, the reticle appears to shift off the target — and your bullet follows that shift. You’ll see this two ways at squirrel ranges:

• The image looks slightly blurry/swimmy at distances far from the parallax setting.
• The aim point moves as you shift your head, if your eye isn’t dead-center.

It’s small, but on a target the size of a golf ball it’s enough to miss a head.

A 50-yard zero, and why it works up close

For squirrels, a 50-yard zero is the classic all-around choice — it matches a rimfire scope’s typical parallax distance and the ranges you actually shoot. At the closer 20–40-yard shots that make up most treetop work, a .22’s bullet has barely started to drop, so the difference between your aim and your hit is tiny — far smaller than a squirrel’s head. Practically, you hold dead-on the head from about 20 to 50 yards and the bullet lands where you look.

Edge case Why not a 25-yard zero for close work?

You can zero at 25 yards, and some do. But a .22’s arc crosses the line of sight twice; a 50-yard zero keeps the bullet within a small band of your aim across the whole 20–50-yard window, while a 25-yard zero lets the bullet climb a bit higher in the middle of that range. For a head-sized target across mixed treetop distances, the 50-yard zero is the more forgiving single setting. The real point: know your zero and how far off the aim point sits at the ranges you shoot — then hold accordingly.

Centered eye behind the scope cancels parallax shift Hold dead-on the head — drop is tiny at 20–50 yds

Check your understanding

Knowledge check

You're setting up a .22 for squirrels. Which scope-and-zero choice fits treetop shooting best?

You're setting up a .22 for squirrels. Which scope-and-zero choice fits treetop shooting best?

A rimfire scope (parallax ~50 yds) zeroed at 50 yards A deer scope zeroed at 100 yards No scope — iron sights only are always more accurate up close

Check answer

Knowledge check

On a very close 15-yard shot, the reticle seems to drift off the squirrel's head as you move your head. What's the fix in the field?

On a very close 15-yard shot, the reticle seems to drift off the squirrel's head as you move your head. What's the fix in the field?

Center your eye squarely behind the scope with a full sight picture before firing Re-zero the rifle right there in the field

Check answer

Take it to the woods

Sight-in session: set and confirm your squirrel zero

0/5

Reset

• ⚠ Safety Muzzle safe, finger off the trigger until on target, the whole session.
• Shoot off a solid rest or sandbags so the rifle — not your hands — holds the aim.
• Zero at 50 yards: adjust until the group centers on the bullseye.
• Confirm at 25 and 40 yards; note how far above/below your aim the bullet lands (it should be very little).
• Practice a consistent cheek weld so your eye centers behind the scope every shot.

Sources

• The MeatEater — Rifle Scopes for Small Game. https://www.themeateater.com/gear/gear-hunt/rifle-scopes-small-game
• American Firearms — The Best Rimfire Scopes for Your .22LR. https://www.americanfirearms.org/the-best-rimfire-scopes-for-your-22lr/
• Squirrel Hunting Journal — Adjustable Objective vs. Set Parallax Scopes. https://squirrelhuntingjournal.com/adjustable-objective-vs-set-parallax-scopes/