.280 Ackley Improved ballistics & drop chart
A high-performance 7mm that nips at magnum ballistics on standard powder. These figures are for a representative 150gr bullet at 2950 fps (G1 BC 0.53), zeroed at 100 yards. Your box, barrel and chronograph will vary, run your own numbers in the calculator below.
.280 Ackley Improved drop chart (100-yard zero)
| Range | Velocity | Energy | Drop | Come-up | 10 mph wind |
|---|---|---|---|---|---|
| 100 yd | 2829 fps | 2665 | 0" | 0 MOA · 0 mil | 0" |
| 200 yd | 2710 fps | 2445 | -2.8" | 1.4 MOA · 0.4 mil | 0" |
| 300 yd | 2593 fps | 2239 | -10.4" | 3.3 MOA · 0.97 mil | 0" |
| 400 yd | 2479 fps | 2046 | -23.2" | 5.5 MOA · 1.61 mil | 0" |
| 500 yd | 2367 fps | 1866 | -41.6" | 7.9 MOA · 2.31 mil | 0" |
| 600 yd | 2258 fps | 1697 | -66.2" | 10.5 MOA · 3.07 mil | 0" |
Wind column is a full-value 10 mph crosswind. Use the calculator below to change zero, scope height, wind, altitude and temperature.
Run your own .280 Ackley Improved load
Bullet weight (30–750)
From the box or a chronograph
G1 BC. G7 is more accurate for boat-tails.
Where the rifle is sighted in
Scope centre above bore
Full-value 90° wind
Uphill or downhill angle
Long-range & conditions (twist, Coriolis, atmosphere, truing)
e.g. 8 for 1:8
e.g. 0.264
For stability + spin
Blank = off
For Eötvös
Minor effect
Dialed a real come-up to hit at a known range? Enter it and we calibrate the model to your exact rifle and ammo, the way the pros do.
Come-up & drop chart
| Range | Vel | Energy | Drop | Up (MOA) | Windage | ToF |
|---|---|---|---|---|---|---|
| 50 yd | 2890 | 2780 | -0.2" | 0.4 | 0.2 | 0.05s |
| 100 yd | 2830 | 2666 | 0" | 0 | 0.4 | 0.1s |
| 150 yd | 2770 | 2556 | -0.9" | 0.5 | 0.5 | 0.16s |
| 200 yd | 2711 | 2448 | -2.8" | 1.4 | 0.7 | 0.21s |
| 250 yd | 2653 | 2344 | -6" | 2.3 | 0.9 | 0.27s |
| 300 yd | 2596 | 2244 | -10.4" | 3.3 | 1.1 | 0.33s |
| 350 yd | 2539 | 2146 | -16.1" | 4.4 | 1.3 | 0.38s |
| 400 yd | 2482 | 2052 | -23.2" | 5.5 | 1.5 | 0.44s |
| 450 yd | 2426 | 1961 | -31.6" | 6.7 | 1.8 | 0.5s |
| 500 yd | 2371 | 1872 | -41.5" | 7.9 | 2 | 0.57s |
| 550 yd | 2317 | 1787 | -53" | 9.2 | 2.2 | 0.63s |
| 600 yd | 2263 | 1705 | -66.1" | 10.5 | 2.4 | 0.7s |
Atmosphere
Elevation
Air temperature
How far does this stay lethal?
Retained energy against the guideline for each animal. Tap one for the full verdict.
Lethal range is where the load holds the guideline minimum energy for that class (800/1200/1800/2800 ft-lbs small/medium/large/heavy). A guideline built on published energy figures, not a rule. Bullet construction, shot placement and your local minimum-caliber laws matter as much as energy, especially on dangerous game. Always confirm your own zero and dope on paper.
This calculator is one tap away in the field, free, with your whole hunt.
It is built into the free hunter app, alongside everything you need on the hunt and after it. No app store, no cost, and it all works offline deep in the bush.
.280 Ackley Improved: common questions
What is the bullet drop of the .280 Ackley Improved?
With a 150gr bullet at 2950 fps (G1 BC 0.53) zeroed at 100 yards, the .280 Ackley Improved drops about 10.4 inches at 300 yards, needing roughly 3.3 MOA (0.97 mil) of come-up. See the full table above for every range, and adjust for your own velocity and zero.
How far is the .280 Ackley Improved good for hunting?
Retained energy decides it. With this load the .280 Ackley Improved holds the deer and light-plains-game guideline (about 1200 ft-lbs) out to roughly beyond 600 yards, and the large-game guideline (about 1800 ft-lbs) to roughly 539 yards. Bullet construction and shot placement matter as much as energy.
What is a good ballistic coefficient for the .280 Ackley Improved?
This chart uses a G1 BC of 0.53, a representative value for a typical 150gr hunting bullet in the .280 Ackley Improved. Heavier, more streamlined match and long-range bullets carry higher BCs and drop and drift less; check the figure on your ammo box or bullet spec sheet and enter it in the calculator.
Is the .280 Ackley Improved good for beginners?
A high-performance 7mm that nips at magnum ballistics on standard powder.
Method & sources
- The trajectory. A point-mass solver that steps the bullet downrange under gravity and aerodynamic drag using the standard G1 and G7 drag models, the same models factory ballistic tables and drag-function calculators (JBM, Hornady, Sierra) are built on. A bullet’s drag equals the reference projectile’s drag at the same speed and air density divided by the bullet’s ballistic coefficient. G7 is used for streamlined boat-tail bullets, where it is far more accurate downrange than a single G1 number.
- Truing. Enter a come-up you have actually confirmed on paper at a known range and the solver back-calculates a drag correction so the model matches yourrifle and ammo, absorbing the small errors in advertised BC and chronograph velocity. This is the same “truing” workflow used by Kestrel and Applied Ballistics, and it is what makes a calculator field-accurate.
- Long-range corrections.Spin drift (Litz approximation), horizontal and vertical Coriolis / Eötvös from your latitude and shot bearing, uphill and downhill shot-angle (the improved Rifleman’s rule), and a Miller gyroscopic-stability (Sg) check that warns when a bullet is under-stabilised for your barrel twist. These are the corrections the top-tier solvers include and most calculators ignore.
- The energy.Kinetic energy uses the standard sporting constant (7,000 grains per pound, 32.174 ft/s² for gravity): KE in foot-pounds = weight in grains × velocity in fps squared ÷ 450,436.
- Atmosphere. Altitude and temperature change air density and the speed of sound, following the International Standard Atmosphere, so drop and drift at 8,000 ft in the Karoo or the Rockies are right, not sea-level guesses.
- Wind.Crosswind drift uses the established lag-time method (drift = crosswind × the difference between actual and no-drag time of flight), the standard field approximation for a full-value 90° wind.
- “Enough gun” guidelines. Minimum terminal-energy figures by body size follow widely published hunting guidelines. They are a starting point, not a rule: bullet construction, shot placement and, on dangerous game, minimum-caliber law matter as much as energy.
- Cartridge figures are representative factory-load values; your box, barrel length and a chronograph reading of your own rifle are always the most accurate. Confirm your zero and dope on paper before relying on any chart in the field.
More all-round big game cartridges
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