Arrow Momentum Chart
Complete momentum reference by arrow weight and bow draw weight. Momentum — not kinetic energy — is the best predictor of penetration depth in archery. See values in slug-ft/s across common setups, plus momentum minimums for large game.
🎯 Quick Momentum Calculator
📊 Arrow Momentum by Bow Draw Weight
Values are in slug-ft/s. Assumes a modern compound at each draw weight with a typical hunting arrow at 29 in draw.
| Arrow Weight | 40 lb bow | 50 lb bow | 60 lb bow | 70 lb bow | 80 lb bow |
|---|---|---|---|---|---|
| 350 gr | 0.35 | 0.40 | 0.44 | 0.49 | 0.53 |
| 400 gr | 0.39 | 0.45 | 0.51 | 0.57 | 0.62 |
| 425 gr | 0.41 | 0.48 | 0.54 | 0.60 | 0.65 |
| 450 gr | 0.43 | 0.50 | 0.57 | 0.63 | 0.68 |
| 500 gr | 0.47 | 0.55 | 0.62 | 0.69 | 0.75 |
| 550 gr | 0.50 | 0.59 | 0.67 | 0.74 | 0.80 |
| 600 gr | 0.53 | 0.63 | 0.71 | 0.78 | 0.85 |
🎯 Momentum Minimums by Game
Momentum ranges commonly recommended by heavy-arrow hunters and penetration researchers.
| Game | Min Momentum | Recommended | Typical Setup |
|---|---|---|---|
| Small game / varmint | 0.25 | 0.30+ | 35–45 lb bow, 300 gr arrow |
| Wild turkey | 0.35 | 0.40–0.50 | 45–55 lb bow, 400 gr arrow |
| Whitetail deer | 0.40 | 0.45–0.60 | 50–65 lb bow, 425–500 gr arrow |
| Wild hog | 0.45 | 0.55–0.70 | 55–70 lb bow, 450–525 gr arrow |
| Black bear | 0.50 | 0.60–0.75 | 60–70 lb bow, 450–525 gr arrow |
| Elk | 0.55 | 0.65–0.80 | 60–75 lb bow, 500–550 gr arrow |
| Moose | 0.60 | 0.75–0.90 | 65–80 lb bow, 550–650 gr arrow |
| Dangerous game | 0.70 | 0.90+ | 70–90 lb bow, 650+ gr arrow |
Momentum minimums are not standardized regulations. They come from heavy-arrow and penetration-focused hunting communities, including those influenced by Dr. Ed Ashby's research.
⚖️ Momentum vs Kinetic Energy — Why Both Matter
- Momentum (mass × velocity) correlates strongly with penetration depth through hide, muscle, and bone. Heavier arrows win here.
- Kinetic energy (½ × mass × velocity²) measures total energy delivered at impact. It favors speed.
- For hunting: momentum and FOC together predict terminal performance better than KE alone.
- Heavy, high-FOC arrows carry momentum through tissue with less deflection. This is the core insight of Ashby-style builds.
❓ Frequently Asked Questions
What is arrow momentum?
Arrow momentum is mass multiplied by velocity. In archery, it is commonly expressed in slug-ft/s (grains × fps ÷ 225218). Momentum predicts penetration better than kinetic energy alone, especially on heavy-boned or thick-skinned game.
How much momentum does a deer arrow need?
Most heavy-arrow hunters recommend a minimum of 0.40 slug-ft/s for whitetail deer, with 0.45–0.60 being a stronger target. A 60 lb compound at 425 grains delivering 275 fps produces about 0.52 slug-ft/s.
How much momentum for elk?
Common recommendations run 0.55 minimum and 0.65–0.80 preferred. A 65 lb bow with a 500 grain arrow at 265 fps produces about 0.59. Moving to a 550 grain arrow at 250 fps boosts momentum to about 0.61.
Does momentum matter for target archery?
Less so. Target archers prioritize flat trajectory and repeatability. Momentum matters more for hunting and penetration-focused shooting. Target setups usually run lighter arrows for speed.
Does higher FOC increase momentum?
FOC itself does not change momentum, but the components required to reach high FOC (heavy inserts, heavy broadheads) raise total arrow weight. Higher total weight with the same bow raises momentum. So high-FOC builds tend to have higher momentum too.
What is the difference between momentum and KE?
Momentum is mass × velocity (linear). KE is ½ × mass × velocity² (quadratic). At the same draw weight, KE stays roughly constant across arrow weights, but momentum rises with heavier arrows. Momentum is a better predictor of penetration; KE is a measure of total energy delivered.