Rifle · SAAMI
6mm BR Remington
The 6mm BR Remington is a rimless bottlenecked rifle cartridge introduced by Remington in 1978, formed from a shortened .308 Winchester-family case.
- Caliber
- 0.243″ · 6.18 mm
- Introduced
- 1978
- Case
- Rimless
- Parent
- .308 Winchester
- Primary use
- Target, Varmint
- Status
- Active
- Introduced
- 1978
- Type
- Rifle
- Origin
- United States
- Inventor
- Mike Walker (Remington)
- Manufacturer
- Remington Arms
- Standard
- SAAMI
- Status
- Active
- Availability
- Limited
- Case capacity
- 37.8 gr H₂O
- Twist (typical)
- 1:9.0
- Primer
- Small Rifle
- Case type
- Rimless
- Max pressure
- 58,740 psi, CIP transducer
- Eff. range
- 800 yd
- Max range
- 5800 yd
- Recoil
- 2.9–4.3 ft·lb
Introduced by Remington Arms
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for 6mm BR Remington, 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
- .308 Winchester
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.
CIP TDCC · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 6.18 | 0.243 | ✓ |
| Neck ⌀ | 6.90 | 0.272 | ✓ |
| Shoulder ⌀ | 11.68 | 0.460 | ✓ |
| Shoulder angle | 30° | — | ≈ |
| Base ⌀ | 11.96 | 0.471 | ✓ |
| Rim ⌀ | 12.01 | 0.473 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.37 | 0.054 | ✓ |
| Neck length | 8.18 | 0.322 | ≈ |
| Case length | 39.62 | 1.560 | ✓ |
| Overall length | 55.88 | 2.200 | ✓ |
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. 6mm BR Remington is highlighted below.
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 from 1960s benchrest wildcats; Remington (Mike Walker) introduced it commercially in 1978.
FAQs
- What twist rate does 6mm BR Remington use?
- 6mm BR Remington typically uses a 1:9.0 twist rate.
- What bullet diameter is 6mm BR Remington?
- 6mm BR Remington uses a 0.243″ (6.18 mm) diameter bullet.
- Is 6mm BR Remington still in production?
- 6mm BR Remington is active; typical availability is limited.
- What is 6mm BR Remington used for?
- 6mm BR Remington is primarily used for target, varmint.
- What is 6mm BR Remington based on?
- 6mm BR Remington is derived from the .308 Winchester case.
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 →
