Rifle · Not SAAMI standardized · Not standardizedObsolete
.600 Overkill
.600 Overkill is a belted bottlenecked rifle cartridge of United States origin.
- Caliber
- 0.6181″ · 15.7 mm
- Introduced
- 2000
- Case
- Belted
- Primary use
- Hunting
- Status
- Discontinued
- Obsolete
- Obsolete
- Introduced
- 2000
- Type
- Rifle
- Origin
- United States
- Inventor
- Robert Garnick
- Manufacturer
- Robert Garnick
- Standard
- Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Discontinued
- Availability
- Rare
- Case capacity
- 195 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Magnum Large Rifle
- Case type
- Belted
- Max pressure
- 18,000 psi, SAAMI transducer
- Eff. range
- 250 yd
- Max range
- 1250 yd
- Recoil
- 280.9 ft·lb
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .600 Overkill, so this is the shape gravity alone gives the advertised velocity. Drag would steepen it. The tool below solves real loads through their published G1 or G7 model.
Open in Ballistic Compare- Parent case
- —
Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 15.70 | 0.618 | · |
| Neck ⌀ | 16.40 | 0.646 | · |
| Shoulder ⌀ | 16.40 | 0.646 | · |
| Shoulder angle | 25° | — | |
| Base ⌀ | 16.70 | 0.657 | · |
| Rim ⌀ | 16.30 | 0.642 | · |
| Belt ⌀ | 17.32 | 0.682 | |
| Rim thickness | 1.50 | 0.059 | · |
| Neck length | 16.22 | 0.639 | |
| Case length | 76.00 | 2.992 | · |
| Overall length | 93.00 | 3.661 | · |
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. .600 Overkill is highlighted below.
Missing a dimension for .600 Overkill? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
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.
Connected reference
History
Introduced around 2000 by Robert Garnick.
FAQs
- What twist rate does .600 Overkill use?
- .600 Overkill typically uses a 1:16 twist rate.
- What bullet diameter is .600 Overkill?
- .600 Overkill uses a 0.6181″ (15.7 mm) diameter bullet.
- Is .600 Overkill still in production?
- .600 Overkill is discontinued; typical availability is rare.
- What is .600 Overkill used for?
- .600 Overkill is primarily used for hunting.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
