.327 Federal Magnum

The .327 Federal Magnum is a rimmed revolver cartridge Federal Premium Ammunition and Sturm, Ruger & Co. introduced together in 2007 by lengthening and strengthening the .32 H&R Magnum, itself a lengthened .32 S&W Long dating back to 1878. Federal thickened the case walls and web and changed its heat treatment to let the round run at a much higher pressure ceiling than the .32 H&R Magnum, which is what a “magnum of a magnum” round like this depends on for its added performance. Its bullet is the same .312-inch diameter as its parent cartridges.

The round’s purpose was narrow and specific: to give a compact revolver with room for only five .357 Magnum cartridges in its cylinder a six-round capacity instead, without giving up the larger round’s performance. Because the .327’s case is shorter than the .357 Magnum’s, the same cylinder diameter fits an extra chamber, and full-sized revolvers have since been built with seven or more. Reviewers have generally described the .327 as noticeably more comfortable to shoot than a .357 Magnum from a compact revolver, citing lower recoil and muzzle blast, though it is not without recoil compared to the milder .32 H&R Magnum it replaces.

No free dimensional standard for the .327 Federal Magnum was found independent of Wikipedia’s own uncited infobox, so its case dimensions and pressure rating are recorded here as estimated. Its two published bullet weights and their velocities, tested from both a compact Ruger SP101 and a longer-barrelled Ruger Blackhawk, come from Ballistics By The Inch’s own chronograph testing of factory ammunition and are recorded as verified.