Recoil Calculator
Calculate free recoil energy for any firearm and ammunition combination. 609 firearms, 3,336 loads — or type your own numbers.
Free recoil
Simplified model. These figures come from bullet momentum alone. A cartridge also throws its propellant gas out of the muzzle, and that gas carries momentum the firearm has to answer for — the full free-recoil expression adds a m_charge · v_gas term this page does not compute. It is left out because the database has no powder-charge figure for any of its 3,336 loads, not because the term is negligible: momentum enters the energy as a square, so the gap is modest for handgun cartridges and large for high-capacity rifle cases. Published .50 BMG numbers around 130 J include the gas; the 51 J below does not, and the two are not the same quantity. Free recoil also ignores the gun’s action, muzzle device and how it is held, which is why it is not the same thing as felt recoil. See methodology →
free recoil energy E = p² / (2 × m_firearm)
free recoil velocity v = p / m_firearm
impulse I = p — 1 N·s and 1 kg·m/s are the same unit
Common combinations
Ten familiar pairings, lightest recoil first. Each row takes the median load of its caliber by recoil energy — not the mildest or the hottest — from the 821 loads those ten calibers cover. Click a row to load it into the calculator.
| Weapon▲ | Caliber▲ | Load▲ | Weight (kg)▲ | v₀ (m/s)▲ | Recoil energy (J)▲ |
|---|---|---|---|---|---|
| Ruger 10/22 Carbine | .22 LR | Federal Champion Training - Rimfire, 22 LR, 36 Grain, Copper Plated Hollow Point, 1260 fps | 2.27 | 384 | 0.2 |
| Colt LE6920 (M4A1) | 5.56×45mm NATO | Winchester 5.56mm 64gr Bonded Solid Base Defender | 2.77 | 853 | 2.3 |
| AK-47/AKM | 7.62×39mm | Winchester 7.62 x 39mm 123gr Full Metal Jacket USA | 3.47 | 718 | 4.7 |
| Ruger LCP MAX | .380 ACP | Magtech .380 ACP 95gr FMJ | 0.30 | 290 | 5.3 |
| Glock 17 Gen5 | 9×19mm Parabellum | Winchester 9mm Luger 124gr Full Metal Jacket USA | 0.63 | 348 | 6.2 |
| Springfield 1911 Loaded | .45 ACP | Speer .45 ACP 185gr Gold Dot HP | 1.11 | 320 | 6.7 |
| M1 Garand | 30-06 Springfield | Norma 30-06 Springfield 165gr Nosler BST | 4.31 | 860 | 9.8 |
| Remington 700 SPS | .308 Winchester | Magtech .308 Winchester 168gr BTHP Match | 3.40 | 808 | 11.4 |
| Remington 870 Express | 12 Gauge | Federal Freight Train Copper Sabot Slug, 12 Gauge, 300 Grain, 3 in, 2000 fps | 3.40 | 610 | 20.7 |
| Barrett M82A1 .50 BMG | .50 BMG | PMP .50 BMG 660gr FMJ | 14.02 | 887 | 51.3 |
Compare any combination — select a weapon and a load above →