Burris Optics Ballistic Calculator: How It Works

The Burris Optics ballistic calculator is a free online tool that estimates bullet drop and trajectory for a given load, environment, and shooting distance. You enter cartridge, bullet weight, muzzle velocity, sight height, zero range, and atmospheric conditions, and it returns a drop chart in inches or centimeters, plus wind drift and time of flight. It is designed to work with Burris scopes that have Ballistic Plex or similar reticles, but it can be used with any scope if you know your bullet’s trajectory.

Formula

The calculator uses the standard ballistic trajectory equations, which are based on Newton’s laws of motion and aerodynamic drag. In simple terms, the bullet’s path is described by:

Drop (inches) = ½ × g × (time of flight)² + (initial vertical velocity × time of flight) + (sight height correction)

Where:

• g = acceleration due to gravity (32.174 ft/s² or 9.81 m/s²)
• Time of flight = distance / average velocity (seconds)
• Initial vertical velocity = muzzle velocity × sine of the launch angle (ft/s or m/s)
• Sight height = distance from the center of the bore to the center of the scope (inches or cm)

In reality, the drag coefficient changes with velocity (supersonic vs. subsonic), so the calculator uses a ballistic coefficient (BC) and a drag model (like G1 or G7) to compute the velocity at each yard. The Burris calculator uses the G1 drag model by default, which is the most common for hunting bullets.

Worked Example

Let’s use the default values from the calculator block above: a finish time of 50 minutes and a distance of 10 km. The average pace is 50 / 10 = 5 min/km, and the average speed is 10 / (50/60) = 12 km/h. That’s the pace and speed you’d see on a running watch, but for a ballistic calculator the inputs are different. For a real example, suppose you are shooting a .308 Winchester with a 168-grain bullet, muzzle velocity 2700 ft/s, sight height 1.5 inches, zeroed at 100 yards. At 300 yards, the calculator might show a drop of -8.2 inches. That means you need to hold 8.2 inches high or adjust your turret by about 2.7 MOA (since 1 MOA ≈ 1.047 inches at 100 yards, so at 300 yards 1 MOA = 3.14 inches). The calculator does this math for you.

How to Use the Burris Ballistic Calculator

To get a useful drop chart, follow these steps:

1. Select your cartridge from the list (or enter custom data).
2. Enter bullet weight (grains), muzzle velocity (ft/s), and ballistic coefficient.
3. Set sight height (distance from bore center to scope center, typically 1.5–2.0 inches).
4. Set zero range (usually 100 or 200 yards).
5. Enter temperature, altitude, and barometric pressure (or use standard conditions).
6. Choose a maximum range and increment (e.g., 25-yard steps).
7. Click calculate to see the drop chart and wind drift.

If you are using a Burris scope with a Ballistic Plex reticle, the calculator can also tell you which hash mark corresponds to a given distance. For example, with a Ballistic Plex in a 3-9×40 scope, the first hash might be 200 yards, second 300, third 400, and so on, depending on your load.

Common Mistakes and Limitations

One common mistake is entering the wrong sight height. If you guess 1.5 inches when it’s actually 2.0 inches, the drop at 500 yards can be off by several inches. Another error is using the wrong ballistic coefficient. The G1 BC is fine for boat-tail bullets, but for very long, low-drag bullets (like the 6.5 Creedmoor with a high-BC bullet), the G7 model is more accurate. The Burris calculator only offers G1, so you may need to convert your bullet’s G7 BC to G1 (or just use a different calculator). Also, the calculator assumes a standard atmosphere and does not account for spin drift or the Coriolis effect, which matter only at extreme ranges (beyond 800 yards). For most hunting scenarios, these are negligible.

Comparison with Other Ballistic Calculators

Burris’s calculator is simple and free, but it lacks some features found in dedicated apps like Applied Ballistics or Strelok Pro. Those apps offer multiple drag models, custom curves, and environmental sensors. However, for a hunter who wants a quick drop chart without a smartphone, the Burris online tool is adequate. It also integrates with Burris scopes’ reticle subtensions, which is a unique advantage if you own one. But if you are a serious long-range shooter, you might want a more advanced calculator that can export data to a Kestrel or a ballistic app.

Cost and Accessibility

The Burris ballistic calculator is free on the Burris website. You don’t need to create an account or download software. It runs in any browser. There is also a mobile version that works on phones, though it is not a native app. If you want a printable drop chart, you can print the page directly. There is no cost, but you need to know your bullet’s muzzle velocity and BC, which you can get from the ammunition manufacturer’s website or a chronograph.

Frequently Asked Questions

Does the Burris ballistic calculator work for any scope?

Yes, it works for any scope as long as you input your sight height and zero range. The drop chart is independent of the reticle. However, if you have a Burris reticle like Ballistic Plex, the calculator can also show which reticle mark to use.

What is the difference between MOA and MIL?

MOA (minute of angle) and MIL (milliradian) are both angular measurements. 1 MOA ≈ 1.047 inches at 100 yards, while 1 MIL ≈ 3.6 inches at 100 yards. The Burris calculator gives drop in inches and MOA, but not in MIL. If your scope is in MIL, you can convert: 1 MIL = 3.44 MOA.

Why does my actual bullet drop differ from the calculator?

Differences come from atmospheric conditions (humidity, pressure), altitude, and the fact that the G1 model is not perfect for every bullet. Also, your actual muzzle velocity may be different from the box. Use a chronograph and verify your drop at 200 and 300 yards to confirm.

Can I use the calculator for shotgun slugs or muzzleloaders?

Yes, you can enter any projectile as long as you know its muzzle velocity and ballistic coefficient. For slugs, the BC is low (around 0.05–0.10), so the drop will be steep. For muzzleloaders, the BC also varies, but the calculator will work.

Does the calculator account for wind?

Yes, it provides wind drift for a given wind speed and direction, usually at a 90-degree full-value wind. You can adjust for half-value winds (45 degrees) by taking half the drift. The calculator does not handle variable wind or mirage.

Is the Burris calculator accurate for long-range shooting beyond 1000 yards?

It can be, but the G1 drag model loses accuracy for very low-drag bullets at transonic speeds. For precision long-range, use a calculator with a G7 model or custom drag curves. For hunting under 600 yards, it is fine.

Related

• Lowe’s Driveway Pavers Calculator: How to Estimate
• Online Concrete Calculator Yards: How to Use
• Pressure Washing Driveway Cost Calculator

in t | Finish time | min | 50 | 0
in d | Distance | km | 10 | 0
out pace | Average pace | min/km | t / d | 2
out speed | Average speed | km/h | d / (t / 60) | 2