.270 Winchester

Winchester developed the .270 in 1923 and unveiled it in 1925 as the chambering for its new bolt-action Model 54, at a time when its main rival for a flat-shooting sporting round was the .300 Holland & Holland Magnum, introduced the same year. The case is a .30-03 Springfield necked down to take a smaller bullet, keeping that parent case’s slightly longer neck rather than the shorter one Winchester had already adopted for the .30-06 Springfield a few years earlier.

Despite the ballistic edge that combination gave it, the .270 was not an immediate commercial success: the .30-06 Springfield already had a head start in the American market through the M1903 Springfield rifles routinely “sporterized” for hunting after military service, and buyers were slow to move to a new, unproven chambering. It has since become one of the most widely used North American big-game hunting cartridges, and Winchester’s original name for it (“270 WCF”, for Winchester Centerfire) has fallen out of common use in favour of the plain .270 Winchester.

All dimensional and pressure figures on this page come from C.I.P.’s own published standard and are recorded as verified; SAAMI, the other body with a stake in this American cartridge, rates its pressure ceiling differently under its own separate test method. Bullet masses and one factory-ammunition velocity point come from Hornady’s current product listing for its 130-grain SST Superformance load, also verified. Three further bullet weights appear in Wikipedia’s own uncited ballistics table without a stated test barrel length, so their bullet masses are recorded as estimated and no velocity is given for them at all: a velocity without a stated barrel length is not a usable figure on this site.