Arrow setup analysis for a 30-inch arrow at 280 fps. Default specs: 398 gr arrow, 8.4 mm shaft diameter.
Total arrow mass for a 30" build: 398 gr = 255 gr shaft (8.5 GPI × 30") + 143 gr components (point + insert + nock + fletching).
KE: 69.3 ft·lbf — Momentum: 0.495 slug·ft/s
| Distance | Velocity | KE (ft·lbf) | Momentum (slug) |
|---|---|---|---|
| 0 yd | 280.0 fps | 69.3 ft·lbf | 0.495 |
| 10 yd | 275.0 fps | 66.8 ft·lbf | 0.486 |
| 20 yd | 270.1 fps | 64.5 ft·lbf | 0.477 |
| 30 yd | 265.2 fps | 62.2 ft·lbf | 0.469 |
| 40 yd | 260.5 fps | 60.0 ft·lbf | 0.460 |
| 50 yd | 255.8 fps | 57.9 ft·lbf | 0.452 |
This build pairs a slightly long cut with a modern mid-speed compound launch. At 30 inches the shaft is suited to longer draw lengths, adding a touch of forward weight and a calmer, more stable flight, and 280 fps is the kind of speed produced by mainstream hunting compounds tuned for a balance of speed and forgiveness. Together they finish at about 398 grains, which is what drives the kinetic energy and momentum figures in the table above.
Because this is a slightly long cut, the extra column length weakens the dynamic spine slightly, so a marginally stiffer shaft often tunes best. The launch matters too: with a modern mid-speed compound launch, the dynamic-spine reaction is dominated by a versatile setup that flattens trajectory without giving up the stability a moderate arrow weight provides. Pick a static spine that lands stiff once this 30" shaft and your point weight are factored in, then confirm it with bare-shaft or paper tuning.
At roughly 69.3 ft·lbf this is large-game kinetic energy — this is solid large-game energy, covering mule deer, black bear, and wild hog where deeper penetration through heavier bone and muscle is needed. Keep in mind that a slightly long cut at 280 fps is only the starting point; broadhead choice and shot placement still decide the outcome more than the headline energy number.
A modern mid-speed compound launch pushing roughly 398 grains yields about 0.495 slug·ft/s of momentum. That is moderate penetration potential: momentum sits in the moderate range, giving dependable penetration on soft tissue while still favouring shot placement over brute force. Momentum, more than raw kinetic energy, predicts how a 30" arrow holds up against bone and angled entry.
For a slightly long cut launched at 280 fps, dial in rest centre-shot and timing first, then verify broadhead flight against field points at distance. A versatile setup that flattens trajectory without giving up the stability a moderate arrow weight provides — so re-check the tear any time you change point weight, since that shifts the dynamic spine on a 30" shaft more than most archers expect.