.17 HMR
.17 HMR | ||||||||||||
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Produced | 2002–present | |||||||||||
Specifications | ||||||||||||
Parent case | .22 WMR | |||||||||||
Case type | Rimmed, bottleneck | |||||||||||
Bullet diameter | .172 in (4.4 mm) | |||||||||||
Land diameter | .168 in (4.3 mm) | |||||||||||
Neck diameter | .190 in (4.8 mm) | |||||||||||
Shoulder diameter | .238 in (6.0 mm) | |||||||||||
Base diameter | .238 in (6.0 mm) | |||||||||||
Rim diameter | .286 in (7.3 mm) | |||||||||||
Rim thickness | .05 in (1.3 mm) | |||||||||||
Case length | 1.058 in (26.9 mm) | |||||||||||
Overall length | 1.349 in (34.3 mm) | |||||||||||
Primer type | Rimfire | |||||||||||
Maximum pressure | 26,000 psi (180 MPa) | |||||||||||
Ballistic performance | ||||||||||||
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Source(s): Hornady[2] |
.17 Hornady Magnum Rimfire, commonly known as the .17 HMR, is a
Development
The .17 HMR round is similar to rounds developed by dedicated rimfire wildcatters who worked to create a rimfire cartridge with an exceptionally flat trajectory. These wildcatters were seeking to match the ballistics of the obsolete 5mm Remington Rimfire Magnum, which was made from 1970 to 1974, and was to that point the fastest rimfire cartridge ever produced.[5] With 5 mm diameter barrels and bullets being virtually unavailable at the time (the 5mm RMR was the last commercial 5 mm round until the 2004 release of the centerfire .204 Ruger), the commercially available .17 caliber became their bullet of choice. The .22 Winchester Magnum Rimfire was the logical parent case, rather than the 5mm RMR (with its unique case head size, which requires a significantly different bolt and magazine) because it was commonly available, and it is a far larger and stronger case than the next largest, the .22 Long Rifle. The .17 caliber wildcats not only met but far exceeded the 5mm RMR's velocities and flat trajectory. The accuracy of these cartridges was also quite good. 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
Availability
Cartridges for .17 HMR come with bullets that weigh 15.5 grains (1.00 g), 17 grains (1.1 g), and 20 grains (1.3 g), and come in designs such as
A growing number of companies offer .17 HMR ammunition.
Examples of
Citing safety concerns about the round's use in semi-automatic firearms, Remington issued a product safety warning and recall notice.[10][11]
.17 Hornady Mach 2
Following the success of the .17 HMR, the .17 Hornady Mach 2 was introduced in early 2004. The .17 HM2 is based on the .22 LR (slightly shorter in case length) case necked down to .17 caliber using the same bullet as the HMR but at a velocity of approximately 2,100 feet per second (640 m/s) in the 17-grain (1.1 g) polymer tip loading.
See also
References
- ^ PMC ammunition site
- ^ "Hornady .17 HMR Page". Archived from the original on 2007-09-27. Retrieved 2007-09-25.
- ^ "New Ruger 77/17 in .17 HMR Rimfire Bolt-Action Rifles". Retrieved 2022-10-24.
- ^ a b "The .17 Hornady Magnum Rimfire". Archived from the original on 29 September 2007. Retrieved 2007-09-25.
- ^ "Magnum Rimfire Comparison: .17 HMR, 5mm Rem. RF Mag, and .22 WMR". Archived from the original on 29 September 2007. Retrieved 2007-09-25.
- ^ Centurion resumed manufacture of 5mm RMR in 2007.
- ^ "The Borchardt Rifle Corp. sells parts to convert Ruger revolvers to .17 HMR". Archived from the original on 2012-03-22. Retrieved 2011-10-09.
- ^ "Ammo Roundup: .17 HMR". Archived from the original on 2009-09-25. Retrieved 2007-09-25.
- ^ "Henry Golden Boy Rifle". www.henryusa.com. Retrieved 2023-04-06.
- ^ ".17 HMR Semi-Auto Firearm Safety Issues". Archived from the original on 2012-02-25. Retrieved 2009-11-21.
- ^ "Safety Warning And Recall Notice". Archived from the original on 12 February 2010. Retrieved 2010-02-06.
External links
- Varmint Al's Field Testing the .17 HMR
- The Hornady Podcast conversation with Steve Hornady, Hornady Director of Engineering, Mitch Mittelstaedt and Hornady Senior Ballistics Scientist, Dave Emary.