The .270 WSM (Winchester Short Magnum) is a centerfire rifle cartridge introduced in 2002, delivering .277-caliber magnum performance from a short, fat case that fits compact short-action rifles. It is a flat-shooting big-game and long-range hunting cartridge.

The .270 WSM was introduced by Winchester in 2002 as part of the short-magnum family, applying the same concept as the .300 WSM to the .277-caliber bore: magnum performance from a shorter, wider case that fits compact short-action rifles rather than longer magnum actions. It offered .270 shooters a higher-velocity, magnum-class option in a handier rifle. Ballistically the .270 WSM drives .277-caliber bullets — commonly 130 to 150 grains — at high velocity, exceeding the classic .270 Winchester and producing a very flat trajectory well suited to open-country big game at extended range. Its recoil is moderate-to-significant for its class, in keeping with the added velocity over the standard .270. The short, efficient case is its defining structural feature. Like other members of the short-magnum family, its popularity has varied over time relative to standard cartridges, but it established a solid following among hunters wanting magnum .270 performance in a compact rifle, with established rifle and ammunition support. Today the .270 WSM is used for big-game hunting and long-range target shooting, with steady ammunition availability. Its combination of magnum-class .277-caliber velocity in a compact short-action package is why it appeals to .270 shooters seeking extra reach and flatness.

General information about this caliber — not a recommendation for this specific firearm.