.270 Winchester

Know the exact name

At a glance

Cartridge family

Sporting & match rifle

Bullet specification

0.2780 in / 7.061 mmBullet maximum

Factory examples

21 loadsSelected, sourced examples below

Weight in cited examples

130–150 grGrains measure mass, not powder charge

.270 Winchester is identified by its complete cartridge designation. The resource-table alternative is 270 Win. A caliber number, bullet diameter, or family resemblance on its own does not identify ammunition compatibility.

Dimensions: open the exact dimensional drawing ↗. The displayed number is bullet maximum, rather than an assertion that every manufactured projectile or barrel has this exact diameter.

Origins & evolution

Background & development

Winchester introduced the .270 in 1925 in the Model 54 rifle, following development work that Sierra dates to 1923. The cartridge belonged to the .30-06-sized case family but used a .277-inch bullet, giving it a different balance of bullet weight and velocity from the established .30-caliber sporting rounds.

Writer Jack O’Connor became its most influential public advocate. His hunting and writing helped connect the cartridge with sheep, mule deer and other open-country game, while Townsend Whelen also praised its sporting qualities. That association between a cartridge, a recognizable hunting style and a prominent writer was a major part of its commercial history. The .270 subsequently appeared in many rifle types and outlasted numerous newer competitors. Its enduring identity rests on the original long-action sporting design; later cartridges carrying the number .270, including the WSM, are separate developments.

Historical sources: Sierra: .270 Winchester cartridge history ↗

Construction changes the story

Loads, variations & specialty offerings

In the cited .270 Winchester examples, bullet weights are 130, 136, 140, 145, 150 grains. These are the weights actually present in this source selection, not a claim that every possible loading is listed.

Bullet construction background: Hornady: anatomy of a bullet ↗. Exact product descriptions and velocities are cited in the factory table.

From the factory catalog

Explore the published data

Ballistics you can inspect

Select a legend entry to add or remove its line. Hover or tap a plotted point, or use the position slider. With the graph focused, arrow keys move the inspector. Solid dots identify source points; dashed connectors show estimates between them. Load construction, pressure category, and test setup can differ even at the same grain weight.

How to interpret the comparison

Changing bullet weight also often changes bullet design and propellant choice. Two curves are comparisons of the listed products, not a controlled experiment proving that bullet weight alone caused the difference. Catalog downrange points are projections under the maker’s conditions; barrel-study points are recorded observations in the study firearm.

Direct answers

Common questions

Keep exploring

Related references

Painted tips or polymer tips? Read the visual identification guide →

Browse the cartridge and gauge guides → · Return to the diameter comparison →

Trace the facts

Sources & methodology

Compiled by 2A Ledger from the linked standards, manufacturer publications, and identified test records. Checked October 18, 2026. Historical tests and older catalogs retain their original dates; a listing here does not establish current availability.

1. SAAMI: dimensional drawing · PDF p. 101 ↗
2. Sierra: .270 Winchester cartridge background ↗
3. Federal · PDF pp. 56–57 ↗
4. Federal · PDF pp. 58–59 ↗
5. Federal · PDF pp. 52–53 ↗
6. Hornady · PDF p. 185 ↗

Diameter figures preserve the cited drawing convention. Inch–millimeter conversion uses exactly 25.4 mm per inch. Factory specifications describe the maker’s test setup; your firearm, ammunition lot, temperature, and measuring method can produce different results. This is an educational factory-ammunition reference, not a reloading manual.