.17 Winchester Super Magnum
.17 Winchester Super Magnum, is a rimfire rifle cartridge developed by the ammunition company Winchester in 2012. It descended from the .27 caliber nail-gun blank by necking down the blank case to take a .17 caliber (4.5 mm) bullet. Initial loadings were with a 20-grain bullet, delivering muzzle velocities around 3,000 ft/s .
|17 Winchester Super Magnum|
|Place of origin||United States|
|Parent case||.27 caliber nail gun blank|
|Case type||Rimfire, bottleneck|
|Bullet diameter||.172 in (4.4 mm)|
|Neck diameter||.197 in (5.0 mm)|
|Shoulder diameter||.269 in (6.8 mm)|
|Base diameter||.269 in (6.8 mm)|
|Rim diameter||.333 in (8.5 mm)|
|Rim thickness||.066 in (1.7 mm)|
|Case length||1.200 in (30.5 mm)|
|Overall length||1.440 in (36.58 mm) to 1.590 in (40.39 mm)|
Factory ammunition is available from Winchester, Federal, American Eagle, and more recently, Hornady.
Hornady 17 Win Super Mag and Federal Ammunition American Eagle® 17 Win. Super Magnum Archived 2015-09-25 at the Wayback Machine cartridges are currently only available with 20-grain polymer-tipped projectiles rated at 3,000 FPS at the muzzle.
Several options from Winchester are available, including Varmint HV 17 Winchester Super Magnum with a 20-grain polymer-tipped projectile rated at 3,000 FPS, Varmint HE 17 Winchester Super Magnum with a 25-grain polymer-tipped projectile rated at 2,600 fps, and Varmint-X 17 Winchester Super Magnum which is available with a lead-free 15-grain polymer tipped projectile, rated at 3,300 FPS.
Currently, rifles firing the 17 WSM are the Savage B-Mag bolt action, heavy barrel B-mag target edition. Ruger Model 77/17, Winchester 1885 Low Wall single shot, and the semi-automatic Franklin Armory F-17. The F-17 is the first gas-piston operated rimfire firearm designed to handle the higher pressures of this cartridge. Also recently Jard Inc. joined this list with their J71 17 WSM AR 15 rifle. 
- "American National Standard Voluntary Industry Performance Standards for Pressure and Velocity of Rimfire Sporting Ammunition for the Use of Commercial Manufacturers" (PDF). Archived from the original (PDF) on 2017-02-02. Retrieved 2017-01-25.
- "The 17 Winchester Super Magnum". Archived from the original on 2013-01-28. Retrieved 2013-01-23.
- "Savage .17 Winchester Super Magnum Rimfire Rifle – SHOT Show 2013". Retrieved 2013-01-23.
- "World's Fastest Rimfire Round: Winchester .17 Super Magnum". Retrieved 2013-01-23.
- "First Ever Functional Gas Operated Rimfire from Franklin Armory". Retrieved 2014-01-21.