It was developed by necking down a .22 Winchester Magnum Rimfire case to take a .17 caliber (4.5mm) projectile.

However, the downrange energy of the 5mm RMR is superior to both .22 WMR and .17 HMR, so there is still potential in the 5 mm rimfire for wildcatters.

[6] Hornady, in conjunction with Marlin Firearms and Sturm, Ruger & Co. (manufacturers in the rimfire rifle market), followed much the same path.

The terminal ballistics of the lightweight expanding bullets limit the .17 HMR to small game animals and varmints.

Examples of bolt-action or lever-action rifles that are chambered for (or have variants chambered for) .17 HMR include Armscor M1700, Browning T-Bolt, CZ 452, Henry Golden Boy,[9] Ruger Model 96, Sako Quad, Savage 93, Steyr Zephyr II, Marlin 917 and Weihrauch 60J.