Rifle · SAAMI
.300 HAM'R
Wilson Combat's AR-15 compatible .30-caliber hunting cartridge.
- Caliber
- 0.308″ · 7.823 mm
- Introduced
- 2018
- Case
- Rimless
- Parent
- 5.56x45mm NATO
- Primary use
- Hunting, Self-Defense
- Status
- Active
- Introduced
- 2018
- Type
- Rifle
- Origin
- United States
- Inventor
- Wilson Combat
- Manufacturer
- Wilson Combat
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 35 gr H₂O
- Twist (typical)
- 1:15
- Primer
- Small Rifle
- Case type
- Rimless
- Max pressure
- 57,500 psi
- Eff. range
- 300 yd
- Max range
- 700 yd
- Recoil
- 6–9 ft·lb
Introduced by Wilson Combat
Ballistics
Published velocity/energy data isn't available for .300 HAM'R. Parent case: 5.56x45mm NATO.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
SAAMI · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.82 | 0.308 | ✓ |
| Neck ⌀ | 8.43 | 0.332 | ✓ |
| Shoulder ⌀ | 9.26 | 0.365 | ✓ |
| Shoulder angle | 30° | — | ✓ |
| Base ⌀ | 9.55 | 0.376 | ✓ |
| Rim ⌀ | 9.60 | 0.378 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.14 | 0.045 | ~ |
| Neck length | 5.94 | 0.234 | ≈ |
| Case length | 40.72 | 1.603 | ✓ |
| Overall length | 57.40 | 2.260 | ✓ |
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. .300 HAM'R is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
2 reloading powders listed for .300 HAM'R, fastest to slowest. Cross-reference in the finder →
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Lineage
Connected reference
History
Developed by Wilson Combat and introduced in 2018 as an AR-15 compatible hunting cartridge. Based on the .223/5.56 case dimensions for bolt-face compatibility. Approved for deer hunting in straight-wall cartridge states. SAAMI standardized in 2021.
FAQs
- What twist rate does .300 HAM'R use?
- .300 HAM'R typically uses a 1:15 twist rate.
- What bullet diameter is .300 HAM'R?
- .300 HAM'R uses a 0.308″ (7.823 mm) diameter bullet.
- Is .300 HAM'R still in production?
- .300 HAM'R is active; typical availability is common.
- What is .300 HAM'R used for?
- .300 HAM'R is primarily used for hunting, self-defense.
- What is .300 HAM'R based on?
- .300 HAM'R is derived from the 5.56x45mm NATO case.
- What are the best powders for .300 HAM'R?
- Reloading powders commonly listed for .300 HAM'R include Lil'Gun, IMR 4227.
Sources & provenance
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Standard SAAMI — SAAMI Announces Acceptance of New 300 HAM'R Cartridge · grain_ballistics, representative_gun archived
- Manufacturer Wilson Combat — Lehigh Defense 300 HAM'R | 110gr, Lehigh TME, 20/Box · grain_ballistics, representative_gun archived
- Manufacturer Wilson Combat — 300 HAM'R | 125gr, Lehigh Defense CC, 20/Box · grain_ballistics, representative_gun archived
- Manufacturer Wilson Combat — 300 HAM'R | 130gr, Speer HAM'R HOT-CORE, 20/Box · grain_ballistics, representative_gun archived
- Manufacturer Wilson Combat — 300 HAM'R | 150gr, Speer HAM'R Boat Tail SP, 200/Carton · grain_ballistics, representative_gun archived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 21 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →