Rifle · SAAMI
.270 Winchester
Jack O'Connor's cartridge of choice for nearly 40 years of outdoor writing, which gave it a permanent audience.
- Caliber
- 0.277″ · 7.036 mm
- Introduced
- 1925
- Case
- Rimless
- Parent
- .30-03 Springfield
- Primary use
- Hunting
- Status
- Active
- Introduced
- 1925
- Type
- Rifle
- Origin
- United States
- Inventor
- Winchester
- Manufacturer
- Winchester Repeating Arms
- Standard
- SAAMI
- Status
- Active
- Availability
- Abundant
- Case capacity
- 67.2 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Large Rifle
- Case type
- Rimless
- Max pressure
- 65,000 psi, SAAMI transducer
- Eff. range
- 500 yd
- Max range
- 4850 yd
- Recoil
- 16–22 ft·lb
Introduced by Winchester Repeating Arms
Ballistics
Published velocity/energy data isn't available for .270 Winchester. Parent case: .30-03 Springfield.
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 · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.04 | 0.277 | ✓ |
| Neck ⌀ | 7.82 | 0.308 | ✓ |
| Shoulder ⌀ | 11.20 | 0.441 | ✓ |
| Shoulder angle | 17.5° | — | ✓ |
| Base ⌀ | 11.96 | 0.471 | ✓ |
| Rim ⌀ | 12.01 | 0.473 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.24 | 0.049 | ✓ |
| Neck length | 9.75 | 0.384 | ≈ |
| Case length | 64.52 | 2.540 | ✓ |
| Overall length | 84.84 | 3.340 | ✓ |
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. .270 Winchester is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
37 reloading powders listed for .270 Winchester, 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.
Firearms chambered in .270 Winchester
Lineage
Necked down; same 2.540 in. case length as the .30-03
Connected reference
History
Introduced by Winchester in 1925 as a necked-down .30-03 Springfield (it is often described as a necked-down .30-06). Legendary gun writer Jack O'Connor championed it for 50 years. One of the most popular hunting cartridges ever.
FAQs
- What twist rate does .270 Winchester use?
- .270 Winchester typically uses a 1:10 twist rate.
- What bullet diameter is .270 Winchester?
- .270 Winchester uses a 0.277″ (7.036 mm) diameter bullet.
- Is .270 Winchester still in production?
- .270 Winchester is active; typical availability is abundant.
- What is .270 Winchester used for?
- .270 Winchester is primarily used for hunting.
- What is .270 Winchester based on?
- .270 Winchester is derived from the .30-03 Springfield case.
- What are the best powders for .270 Winchester?
- Reloading powders commonly listed for .270 Winchester include Reload Swiss RS60, Winchester 760, S243, Power Pro 4000-MR, among 37 suitable options.
Sources & provenance
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Secondary .30-03 Springfield — Wikipedia (lists .270 Winchester as based on reducing .30-03 neck to retain same overall length/shoulder) · parent_cartridge
- Secondary .270 Winchester — Wikipedia (parent case field + necked-down .30-03 statement, refs to American Rifleman/RifleShooter) · parent_cartridge
- Secondary Cartridge Legacies: The .30-06 Springfield Family Tree — American Hunter (NRA) · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 221 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
