Accuracy Differences Between the .17 HMR & the .22

The .17 HMR, or Hornady Magnum Rimfire, is a "Wildcat" cartridge that was developed by shooting enthusiasts in response to the demise of the 5 mm Remington Magnum. The .17 HMR offers superior ballistic performance in certain areas, such as velocity and trajectory, to the .22 WMR, Winchester Magnum Rimfire, because it is faster and flatter shooting. The only area where the .22 WMR is superior is in muzzle energy, but the .17 HMR retains more energy downrange. Because of its superior ballistics, the .17 HMR proves to be more accurate than the .22 WMR.

  1. The .17 HMR

    • The .17 HMR went into production in 2002. It is made from a necked-down .22 WMR, Winchester Magnum Rimfire case in order to accept the .17-caliber bullet, which is actually .172 inches, and a very light 17 grains. Using the .22 WMR case allowed for much simpler production of the rifle because existing .22 WMR actions could be used. This would allow the production of a .17 HMR rifle with only having to change the chamber. The .17 HMR was meant to be superior to the .22 WMR, and it is, in two of three main areas.

    The .22 WMR

    • The only .22 cartridge worth comparing to the .17 HMR, is the .22 WMR, or Winchester Magnum Rimfire, which was introduced in 1959, and was meant to be the most powerful rimfire cartridge around. The .22 WMR uses a metal-jacketed bullet with a standard weight of 40 grains.

    Muzzle Velocity

    • Muzzle velocity, or MV, refers to speed, in feet per second, that a bullet leaves the barrel. MV directly effects how far a bullet will go. MV is also a component of muzzle energy. The .17 HMR has a MV of 2,550 feet per second. The .22 WMR is 1,910 fps. Obviously, the .17 HMR is the winner in this category. Even the high-performance 30-grain .22 WMR can only manage an MV of 2,200 fps.

    Ballistic Cofficient

    • Ballistic coefficient, or BC, is a number that relates to how well a bullet flies. Bullets with high BC fly better than ones with low BC. The .17 HMR has a BC of .123.The .22 WMR has a BC of .090, and the high-performance .22 WMR is .095. The .17 HMR achieves its superior BC by way of the addition of a plastic ballistic tip on the end of the bullet, making it more streamlined than the .22s. Here, the .17 HMR wins again because it will fly better. For instance, the .17 HMR only drops 5.5 inches at 200 yards. The .22 WMR drops 19 inches. The high-performance .22 WMR drops 16.55 inches.

    Muzzle Enerby

    • Muzzle energy, or ME, is a calculation of the kinetic energy of a bullet as it exits the muzzle of the firearm. The higher the ME, the greater the destructive force exerted on the target. This is the only area where the .17 HMR with an ME of 245 foot-pounds falls short, but only to the .22 WMR. The .22 WMR has an ME of 324 foot-pounds. Overall, the .17 HMR will do everything the .22 WMR will do, and do it farther and faster. The difference in ME is negated at downrange range because the .17 HMR has 72 foot-pounds, to the .22 WMR's 67, at 200 yards. This is a direct result of the .17 HMR's greater MV and BC.

    Accuracy

    • The .17 HMR will shoot 1-inch groups at 100 yards. This is an accuracy of less than 1 MOA, or minute of angle. 1 MOA at 100 yards is 1.047 inches. The .22 WMR shots 1.5-inch groups at 100 yards for an MOA of 1.5. This would result in 2-inch groups for the .17 HMR at 200 yards and 3-inch groups for the .22 WMR at 200 yards, although, with a bullet drop of over 1.5 feet at 200 yards, the .22 WMR is really only good out to about 150 yards. The winner is the .17 HMR.