The .17 Mach 2 (.17 HM2) was developed by Hornady and CCI in 2004. It uses the .22 Long Rifle case necked down to .17 caliber, bridging the gap between .22 LR and .17 HMR. Suitable for small varmints and targets to 150 yards.
Type: Rimfire Rifle
Introduced: 2004, USA
Bullet diameter: 0.172" (4.37 mm)
Case length: 0.613" (15.57 mm)
Max pressure: 24,000 PSI
Rim type: rimfire
Muzzle velocity: 2050–2100 fps
Primary use: varminting, target
Production status: Active