Short answer: a chronograph measures your projectile's real velocity. That lets you calculate actual FPE, see shot-to-shot consistency, find your usable shot count, tune a regulator and pick the best ammo. Modern radar chronographs don't need to sit in front of the muzzle, and many also connect to phone apps for shot strings and ballistic data.
What a Chronograph Tells You
- Velocity of each shot
- Energy (FPE), calculated from velocity and projectile weight
- Consistency: extreme spread and standard deviation
- Shot count: where velocity falls off as tank pressure drops
- Ballistic coefficient (on some models), for accurate drop charts
Chronographs We Carry
| Model | Key specs (per product page) |
|---|---|
| FX Pocket Chronograph PRO | Doppler radar, 200 to 4500 fps, BC calculation up to 1280 fps, environmental sensors, PRS mode, Bluetooth, 2-inch TFT display, USB-C. Includes tripod and weapon mount |
| FX Pocket Chronograph D1 | Palm-size radar unit, up to 1250 fps, built-in screen for velocities and stats. FX Radar app adds shot strings, rifle and bullet libraries and drop charts |
| Athlon Rangecraft Velocity PRO | Doppler radar, 65 to 5000 fps, .17 to .50 in diameter projectiles, 6+ hour battery, Athlon Ballistics Lite app |
| FX True Ballistics Chronograph | Radar that reads four velocities from 0 to 300 yards to determine actual G1/G7 BC, 400 to 4000+ fps, standard deviation and spread, subsonic yardage |
Shop all chronographs.
Which Chronograph Should You Get?
- Small-bore airgun shooters: the FX D1 covers velocities up to 1250 fps in a very small unit.
- All-round and firearms too: the FX PRO (200 to 4500 fps) or Athlon Rangecraft (65 to 5000 fps).
- Long-range BC data: the FX True Ballistics measures downrange velocities to determine actual BC.
How to Use a Chronograph to Tune
- Fill to the rated pressure.
- Shoot a full string and record every velocity.
- Find the plateau. On regulated rifles, velocity stays flat until tank pressure nears the regulator setting.
- Adjust in small steps. AEA, for example, recommends no more than a quarter turn on its regulators and says a chronograph will help measure results.
- Compare ammo. Shoot groups and strings with each pellet or slug and keep the most consistent one.
Why Radar Beats Optical Gates
Athlon notes that the Rangecraft is not mounted to the firearm, so it won't affect zero or barrel harmonics and isn't triggered by muzzle blast. FX says the D1 measures in any weather and even in the dark.
Frequently Asked Questions
Do I need a chronograph for my air rifle?
It isn't required, but it is the only way to know your true velocity, energy and shot count, and it is essential for regulator tuning.
Which chronograph works best for airguns?
Radar units like the FX Pocket Chronograph D1 or PRO and the Athlon Rangecraft work well. Choose based on velocity range and app features.
Can a chronograph measure ballistic coefficient?
Some can. The FX Pocket Chronograph PRO offers BC calculation, and the FX True Ballistics determines G1/G7 BC from downrange readings.
Will a moderator affect radar chronograph readings?
Athlon says the Rangecraft can read projectiles from guns with suppressors, muzzle brakes and other muzzle devices.
How do I calculate FPE from my chronograph?
FPE = weight in grains x velocity squared / 450,240. See our FPE guide.
Always follow the manufacturer manual, wear eye protection, and know your local laws before buying, carrying or shooting an airgun.
Talk to The Pellet Shop
Have a question about a specific rifle, caliber or setup? Visit our showroom in Westbury, NY, call or text (718) 450-4146, or email info@ThePelletShop.com. You can also browse every airgun we carry online. Specs in this article come from our product pages and manufacturer documentation and can change, so check the current product page before you buy.