Estimating Range

You glass a groundhog feeding at what looks like “about 200 yards.” You squeeze off a shot and the animal doesn’t move — you watch it duck into the burrow unbothered. The rangefinder you left in the truck would have told you it was actually 265 yards. That extra 65 yards dropped your bullet 4 inches below the vitals. Varmint hunting has no margin for guessed yardage.

Quick recall

Quick recall — what does your rifle's zero distance tell you about shots at longer ranges?

Quick recall — what does your rifle's zero distance tell you about shots at longer ranges?

The bullet stays at the same point of impact at any distance Beyond the zero the bullet drops below the line of sight, increasing with distance The bullet climbs above the line of sight at longer ranges

Check answer

Why range matters more on varmints

A groundhog’s vital zone — the heart-and-lung area on the chest — is roughly the size of a baseball. A whitetail’s vital zone is a paper plate. Varmint hunting forgives almost nothing.

At 200 yards, a typical .22-250 load is shooting flat enough that a 25-yard range error adds less than an inch of vertical error. But at 300 yards, that same 25-yard error produces 3–4 inches of drop difference — enough to pass clean through thin air where the animal was standing a moment ago.

The why Why groundhogs are hard to range directly

Laser rangefinders work by bouncing a pulse off a solid surface and measuring the return time. A groundhog’s fur absorbs a surprising amount of that pulse, and its body is small — the beam can easily pass around it and range the field behind. Range the burrow mound, a fence post, or a tree near the burrow instead. Those are larger, more reflective surfaces that give a reliable reading.

Method 1: Laser rangefinder

A quality laser rangefinder gives you the distance in under a second and is the gold-standard tool for varmint hunting. Using it well is a practiced skill:

1. Range before the animal appears. Walk or drive the field before your hunt, range every burrow mound and log the distances in a notebook or your phone. When a chuck appears at Burrow 4, you already know it’s 187 yards.
2. Range nearby objects when you can’t range the animal. A fence post six feet from the mound, the mound itself, a large rock — all work better than trying to range a small, furry body.
3. Steady the rangefinder. Handheld jitter at longer ranges can introduce real error. Rest your elbows on your knees or a shooting bag and press the button while breathing steadily.

Method 2: Reticle-based ranging

If you have a mil-dot or MOA-graduated reticle in your scope, you can estimate range from the size the target appears. The formula for mil-based reticles is:

Range (yards) = (target size in yards × 1000) ÷ mils measured

A mature groundhog’s body from nose to rump is roughly 18–20 inches (about 0.5 yard). If that animal measures 2 mils in your reticle at its full body length, the range is:

(0.5 × 1000) ÷ 2 = 250 yards

Edge case First focal plane vs. second focal plane matters here

On a first focal plane (FFP) scope, the reticle markings are accurate at any magnification — you can do mil ranging at any power setting. On a second focal plane (SFP) scope, the reticle markings are only accurate at the scope’s maximum magnification. Using mil ranging at lower magnification on a SFP scope will produce a significantly wrong answer. Check your scope’s manual and set it to max power before doing reticle ranging.

Method 3: Pre-ranging landmarks

This is the most reliable long-game approach for a stand hunter who posts on a known burrow system:

1. Before the season or before your hunt, walk the field with your rangefinder.
2. Identify 4–6 landmarks — fence posts, large rocks, distinctive clumps of grass — at various distances from your planned shooting position.
3. Log each landmark’s distance and note its location relative to the burrows. (“The rotting fence post is 178 yards; Burrow A is 12 yards beyond it at roughly 190 yards.”)
4. When a chuck appears, locate it relative to your known landmarks. Your range estimate is instant and requires no equipment in your hand.

Read the field before you shoot

The diagram below shows a typical Piedmont field setup with burrows, landmarks, and the vantage point. Explore each marker to see the range-estimation technique it represents.

Explore

Tap each marker to see the range-estimation technique for that landmark.

Vantage point Fence post Known burrow Woodland edge

• Vantage point Your elevated position at the edge of cover. Before the hunt, range every burrow and landmark from here and write down the numbers.
• Fence post Pre-ranged at 145 yards. Large, reflective — ideal for the rangefinder beam. When a chuck appears near it you already know the range.
• Known burrow Pre-ranged at 210 yards. Mark it in your notes. When the chuck pops out, you're already dialed or holding the right amount.
• Woodland edge The treeline here is 280 yards. A chuck feeding between the burrow and the trees is somewhere in the 210–280 yard window — tighten the estimate with your reticle.

Make the call — which method, which situation?

Knowledge check

You're set up on a new field and a groundhog appears at a burrow you haven't ranged yet. You have a laser rangefinder in your chest pocket. What's the right order of steps?

You're set up on a new field and a groundhog appears at a burrow you haven't ranged yet. You have a laser rangefinder in your chest pocket. What's the right order of steps?

Shoulder the rifle, then reach for the rangefinder and range while scoped in Estimate by eye — it looks about 200 yards — and shoot Range the burrow mound with the rangefinder first, then shoulder the rifle knowing the distance

Check answer

Knowledge check

You measure a groundhog's body at 2.5 mils in a first focal plane scope. A groundhog's body is about 0.5 yards long. What is the estimated range?

You measure a groundhog's body at 2.5 mils in a first focal plane scope. A groundhog's body is about 0.5 yards long. What is the estimated range?

200 yards 125 yards 500 yards

Check answer

Take it to the woods

Range your field before the hunt

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Reset

• Confirm your rangefinder battery is fresh before the trip.
• Walk or drive the field before hunting and range every burrow mound.
• Write down or voice-memo the ranges: 'Burrow near oak stump — 193 yds.'
• Identify 4–6 landmarks (posts, rocks, trees) and log their distances too.
• If using a mil reticle, confirm whether your scope is FFP or SFP and set it to max magnification if SFP.
• ⚠ Safety Practice the order: rangefinder first, rifle second — never both at once.

Sources

• Mil-dot ranging formula and bracketing technique: https://blog.cheaperthandirt.com/estimating-range-with-a-mil-dot-reticle/
• First vs. second focal plane reticles for ranging: https://www.outdoorlife.com/blogs/master-class/2013/04/mil-dot-reticles-use-mils-estimate-range/
• Pre-ranging landmarks and vantage-point setup for woodchuck hunting: https://www.grandviewoutdoors.com/big-game-hunting/whitetail-deer/woodchuck-hunting-101
• Laser rangefinder best practices for hunting: https://www.atncorp.com/blog/what-is-a-rangefinder
• Groundhog body dimensions (16–32 inches total length): https://www.britannica.com/animal/groundhog