57-N-231U Subsonic
- Cartridge
- 7.62x39mm
- Bullet weight
- 12.55 g
- Reference velocity
- 300 m/s
- Muzzle energy
- 565 J
Specification
The load, and the figures its drawing is made from
IdentityWho makes it, and what it is for.
- Designation
- US
- Maker
- Various
- Country of origin
- Soviet Union
- Introduced
- 1962
- Military load
- Yes
- Widely available
- No
ProjectileThe figures the drawing and the solver start from.
- Bullet type
- FMJ
- Cartridge
- 7.62x39mm
- Bullet diameter
- 7.92 mm
- Bullet weight
- 12.55 g (193.7 gr)
- Sectional density
- 0.286
- Ballistic coefficient (G1)
- 0.4
- Ballistic coefficient (G7)
- 0.2
- Reference velocity
- 300 m/s (984 ft/s)
- Reference barrel
- 415 mm
- Velocity retention exponent
- 0.12
Ballistics
Downrange, solved
Solved at the reference barrel of 415 mm from the G1 coefficient and the load's velocity retention. A different barrel gives a different curve.
At the muzzle
What leaves the barrel
MuzzleThe solver’s figures at the reference barrel, where the curve starts.
- Muzzle energy
- 565 J
- Effective range
- 181 m
- Momentum
- 3.77 kg m/s
- Taylor knockout factor
- 8.5
- Hatcher relative stopping power
- 29
- Energy density
- 1146.3 J/cm²
Downrange
Point by point
The same solution as the chart, at each distance the solver reports.
| Distance | Velocity | Energy | Drop | Time of flight | Mach |
|---|---|---|---|---|---|
| 0 m | 300 m/s | 565 J | 0 cm | 0 s | 0.87 |
| 50 m | 291 m/s | 533 J | 14 cm | 0.169 s | 0.85 |
| 100 m | 283 m/s | 504 J | 57.8 cm | 0.343 s | 0.83 |
| 200 m | 268 m/s | 452 J | 244.4 cm | 0.706 s | 0.78 |
| 300 m | 254 m/s | 406 J | 581.3 cm | 1.089 s | 0.74 |
| 400 m | 241 m/s | 366 J | 1092.1 cm | 1.492 s | 0.70 |
| 500 m | 229 m/s | 329 J | 1803.1 cm | 1.917 s | 0.67 |
| 600 m | 217 m/s | 297 J | 2744.2 cm | 2.365 s | 0.63 |
| 800 m | 196 m/s | 241 J | 5453.6 cm | 3.334 s | 0.57 |
| 1000 m | 177 m/s | 196 J | 9538.3 cm | 4.41 s | 0.52 |
API
The call that returns this record
The same fields, in the same units, from the same endpoint the page reads.
curl --request GET \ --url 'https://api.gunspec.io/v1/ammunition/us-subsonic' \ --header 'X-API-Key: your_key'