Terminal Ascent, 280 Ackley Improved, 155 Grain, Terminal Ascent, 2930 fps
| Manufacturer | Federal |
|---|---|
| Calibre | 7.21 mm (.284") |
| Bullet weight | 155.0 gr · 10.04 g |
| Ballistic coefficient G1 | 0.586 |
| Ballistic coefficient G7 | not published |
| Drag model used | G1 |
| Muzzle velocity | 893.1 m/s · 2930 fps |
| Muzzle energy | 4006 J · 2954 ft·lb |
| Sectional density | 0.275 |
| Form factor | i1 0.469 |
| Category | Hunting |
| Source | Federal website 2026-07-02 (verified) |
Reading these numbers
Only a G1 ballistic coefficient is published for this load, so BallisticApp solves it against the G1 drag table. G1 BC drifts with velocity — the figure below is valid near the muzzle and drops off as the bullet slows.
Muzzle energy of 4006 J (2954 ft·lb) is computed from the bullet weight and muzzle velocity above, not quoted from the catalogue. Sectional density 0.275 describes weight per unit of frontal area; divided by the ballistic coefficient it gives the form factor, which is how much drag the shape adds over the standard projectile.
Among the 177 loads of this bore diameter in the database, this one's G1 BC of 0.586 is higher than 166 of them.
Similar 7.21 mm (.284") loads
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