Rimfire Rifle
.17 Mach 2
The .17 Mach 2 (.17 HM2) was developed by Hornady and CCI in 2004.
- Caliber
- 0.1724″ · 4.38 mm
- Introduced
- 2004
- Case
- Rimfire
- Parent
- .22 Long Rifle
- Primary use
- varminting, target
- Status
- Active
- Introduced
- 2004
- Type
- Rimfire Rifle
- Origin
- United States
- Inventor
- CCI / Hornady / Aguila
- Manufacturer
- Hornady/CCI
- Status
- Active
- Availability
- Common
- Case type
- Rimfire
- Max pressure
- 24,000 psi
- Eff. range
- 150 yd
Ballistics
Published velocity/energy data isn't available for .17 Mach 2. Parent case: .22 Long Rifle.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
CIP TDCC · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 4.38 | 0.172 | ✓ |
| Neck ⌀ | 4.83 | 0.190 | ~ |
| Shoulder ⌀ | 5.74 | 0.226 | ✓ |
| Shoulder angle | 20° | — | ✓ |
| Base ⌀ | 5.74 | 0.226 | ✓ |
| Rim ⌀ | 7.06 | 0.278 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.09 | 0.043 | ✓ |
| Neck length | 2.66 | 0.105 | ≈ |
| Case length | 18.14 | 0.714 | ✓ |
| Overall length | 25.40 | 1.000 | ✓ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. .17 Mach 2 is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Firearms chambered in .17 Mach 2
4 models in the database chamber .17 Mach 2. Browse all →
Lineage
Connected reference
History
The .17 Mach 2 (.17 HM2) was developed by Hornady and CCI in 2004. It uses the .22 Long Rifle case necked down to .17 caliber, bridging the gap between .22 LR and .17 HMR. Suitable for small varmints and targets to 150 yards.
FAQs
- What bullet diameter is .17 Mach 2?
- .17 Mach 2 uses a 0.1724″ (4.38 mm) diameter bullet.
- Is .17 Mach 2 still in production?
- .17 Mach 2 is active; typical availability is common.
- What is .17 Mach 2 used for?
- .17 Mach 2 is primarily used for varminting, target.
- What is .17 Mach 2 based on?
- .17 Mach 2 is derived from the .22 Long Rifle case.
Sources & provenance
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Reference Gun Digest Books — Cartridges of the World (Gun Digest Books, F. C. Barnes) · grain weights
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 20 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →