Velocity classes
Standard-velocity, high-velocity, and subsonic are load descriptions. Their numerical limits and test conditions belong to the exact product. A rifle catalog velocity should not be assumed for a handgun.
THE CARTRIDGE LIBRARY · RIMFIRE
.17 HMR
A small, bottlenecked magnum rimfire cartridge built around a .17-caliber bullet. Its lightweight projectile and factory varmint loads distinguish it from the larger-bullet .22 WMR.
2A Ledger reference desk · Sources checked October 18, 2026
Read the dimensions
- Overall · min–max
- 1.330–1.365 in
33.782–34.671 mm - Case length · max
- 1.064 in
27.026 mm - Bullet maximum
- 0.1725 in
4.382 mm - Rim diameter · max
- 0.294 in
7.468 mm
Know the exact name
At a glance
- Cartridge family
- Rimfire
- Bullet specification
- 0.1725 in / 4.382 mmBullet maximum
- Factory examples
- 6 loadsSelected, sourced examples below
- Weight in cited examples
- 15.5–20 grGrains measure mass, not powder charge
.17 HMR is identified by its complete cartridge designation. The resource-table alternative is 17 Hornady Magnum Rimfire. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.
HMR and WSM are separate cartridges despite sharing a nominal .17-caliber bullet.
Dimensions: open the exact dimensional drawing ↗. The displayed number is bullet maximum, rather than an assertion that every manufactured projectile or barrel has this exact diameter.
Origins & evolution
Background & development
Hornady introduced the .17 Hornady Magnum Rimfire in 2002, working with firearm makers to bring rifles and ammunition to market together. Ruger’s contemporary announcement dates its 77/17 introduction to January of that year. The cartridge used the .22 WMR case family with a smaller .17-caliber bullet, bringing a flatter trajectory to the commercial rimfire market without moving to a centerfire cartridge.
The launch paired light, jacketed, polymer-tipped bullets with rifles intended for small-game and varmint shooting. That coordinated introduction mattered: an interesting cartridge needed affordable factory ammunition and readily available firearms to establish a following. Hornady ballistician Dave Emary later identified the HMR among the products he helped develop. Its success renewed interest in small-caliber rimfires after earlier attempts, including Remington’s 5 mm rimfire, had struggled commercially. HMR’s ancestry also explains why it belongs beside the .22 WMR in a historical discussion, while remaining distinct from Winchester’s later .17 WSM.
Historical sources: Ruger: original 2002 77/17 announcement ↗ · Hornady: interview with developer Dave Emary ↗ · American Rifleman: HMR history and original field evaluation ↗
Construction changes the story
Loads, variations & specialty offerings
Bullet design
Round-nose, hollow-point, and polymer-tipped bullets have different intended roles. A tip or hollow cavity is not a reliable substitute for the maker’s product description.
Specialty products
Target and reduced-noise products may trade velocity or bullet shape for a particular use. Verify reliable operation and the firearm maker’s ammunition restrictions rather than assuming every rimfire product behaves alike.
In the cited .17 HMR examples, bullet weights are 15.5, 17, 20 grains. These are the weights actually present in this source selection, not a claim that every possible loading is listed.
Bullet construction background: Hornady: anatomy of a bullet ↗. Exact product descriptions and velocities are cited in the factory table.
From the factory catalog
15.5 grains
2,525 fps
NTX®
17 grains
2,530 fps
JHP
20 grains
2,375 fps
XTP®
Compare all 6 cited factory load records
| Maker / product | Bullet mass | Published construction | Muzzle velocity | Test barrel | Source |
|---|---|---|---|---|---|
| Hornady83171 | 15.5 gr 1.00 g | NTX® | 2,525 fps 770 m/s | Not stated here; see source | Hornady · PDF p. 182 ↗ |
| Federal770BTL250 | 17 gr 1.10 g | JHP | 2,530 fps 771 m/s | Not stated here; see source | Federal · PDF p. 64 ↗ |
| FederalP770 | 17 gr 1.10 g | SPEER TNT JHP | 2,530 fps 771 m/s | Not stated here; see source | Federal · PDF p. 64 ↗ |
| FederalP771 | 17 gr 1.10 g | HO V R -M N A A X D ® Y® | 2,530 fps 771 m/s | Not stated here; see source | Federal · PDF p. 64 ↗ |
| Hornady83170 | 17 gr 1.10 g | V-MAX® | 2,550 fps 777 m/s | Not stated here; see source | Hornady · PDF p. 182 ↗ |
| Hornady83172 | 20 gr 1.30 g | XTP® | 2,375 fps 724 m/s | Not stated here; see source | Hornady · PDF p. 182 ↗ |
Explore the published data
Ballistics you can inspect
Select a legend entry to add or remove its line. Hover or tap a plotted point, or use the position slider. With the graph focused, arrow keys move the inspector. Solid dots identify source points; dashed connectors show estimates between them. Load construction, pressure category, and test setup can differ even at the same grain weight.
Read the original values as accessible tables
.17 HMR: factory velocity downrange
| Exact load | Source | Published points |
|---|---|---|
| 15.5 gr Hornady NTX® | Hornady | 0: 2525; 100: 1830; 200: 1291 |
| 17 gr Federal JHP | Federal | 0: 2530; 50: 2150; 100: 1804 |
| 20 gr Hornady XTP® | Hornady | 0: 2375; 100: 1755; 200: 1274 |
| 17 gr Federal SPEER TNT JHP | Federal | 0: 2530; 50: 2150; 100: 1804 |
| 17 gr Federal HO V R -M N A A X D ® Y® | Federal | 0: 2530; 50: 2194; 100: 1884 |
| 17 gr Hornady V-MAX® | Hornady | 0: 2550; 100: 1902; 200: 1379 |
How to interpret the comparison
Changing bullet weight also often changes bullet design and propellant choice. Two curves are comparisons of the listed products, not a controlled experiment proving that bullet weight alone caused the difference. Catalog downrange points are projections under the maker’s conditions; barrel-study points are recorded observations in the study firearm.
Direct answers
Common questions
What is .17 HMR?
A small, bottlenecked magnum rimfire cartridge built around a .17-caliber bullet. Its lightweight projectile and factory varmint loads distinguish it from the larger-bullet .22 WMR.
What diameter does .17 HMR use?
The cited dimensional standard lists 0.1725 inches (4.382 mm), bullet maximum. This drawing convention is different from a casual caliber nickname.
Are similarly named cartridges interchangeable?
HMR and WSM are separate cartridges despite sharing a nominal .17-caliber bullet.
Are the graph values measured or estimated?
The downrange view uses the exact manufacturer catalog records shown in the source table. Dashed connectors and intermediate inspector values use linear interpolation between the displayed source points. Calculated energy uses the listed bullet mass and velocity.
Does higher energy mean the best load?
Energy is calculated from mass and velocity. It does not establish accuracy, expansion, penetration, pattern density, recoil, or suitability for a particular firearm. Use the exact product documentation and firearm manual.
Trace the facts
Sources & methodology
Skives & petals: read the jacket construction →
Compiled by 2A Ledger from the linked standards, manufacturer publications, and identified test records. Checked October 18, 2026. Historical tests and older catalogs retain their original dates; a listing here does not establish current availability.
- SAAMI: dimensional drawing · PDF p. 16 ↗
- Hornady: cartridge development interview ↗
- Hornady · PDF p. 182 ↗
- Federal · PDF p. 64 ↗
- Ruger: original 2002 77/17 announcement ↗
- American Rifleman: HMR history and original field evaluation ↗
Diameter figures preserve the cited drawing convention. Inch–millimeter conversion uses exactly 25.4 mm per inch. Factory specifications describe the maker’s test setup; your firearm, ammunition lot, temperature, and measuring method can produce different results. This is an educational factory-ammunition reference, not a reloading manual.