Little Bullets but Big Impacts: The 0.17 HMR and 2 Homicide Cases.

Firearms are a leading cause of violent injury and death. Most crime-related shootings and fatalities within the United States involve low-velocity, medium-caliber or large-caliber firearms, such as .380 Automatic Colt Pistol (ACP), 9 mm, 0.40 Smith & Wesson, or 0.45 ACP handguns, or high-velocity firearms, such as Assault Rifle-15 self-loading rifles. Low-velocity, small-caliber rounds, such as the ubiquitous 0.22 long-rifle cartridge, are occasionally encountered in crime-related shootings, but are less common than incidents involving center-fired cartridges. A lesser-known small-caliber cartridge is the 0.17 Hornady Magnum Rimfire (HMR). Like the 0.22 cartridge, the 0.17 cartridge is rim-fired, being contained in a casing that is of similar diameter as a normal 0.22; however, the neck of the casing is tapered down to contain the 0.17 diameter projectile. In contrast to the 0.22, the 0.17 HMR is considered a high-velocity round and is touted as an excellent choice for hunting small game and eliminating varmints. There is limited literature documenting deaths and wounds from these high-velocity, rim-fired, small-caliber bullets. Herein, we describe 2 homicide cases where 0.17 HMR caliber bullets were involved in lethal outcomes.