| Mechanical system | Bolt action, single shot | |
| Caliber | HB17: .177 cal (4.5 mm) HB20: .20 cal (5.0 mm) HB22: .22 cal (5.5 mm) | |
| Magazine capacity | Single Shot | |
| Total length | 12 1/4 inches (31.12 cm) | |
| Weight | 2 1/2 lbs (1.13 kg) | |
| Muzzle velocity | Projectile- .177: up to 525 FPS Projectile- .22: up to 460 FPS | |
| Function | Bolt action | |
| Barrel | Rifled brass, 6 grooves | |
| Safety | Cross Bolt |