The .327 Federal Magnum is a cartridge introduced by Sturm, Ruger and Federal Cartridge, intended to provide the power of a .357 Magnum in six shot, compact revolvers, whose cylinders would otherwise only hold 5 rounds. The .327 Federal Magnum is actually a super magnum having replaced the .32 H&R Magnum as the pinnacle of power in this diameter revolver cartridge.
In the April 2008 issue of the NRA's American Rifleman magazine, Field Editor Bryce Towsley summed up his review of the cartridge as follows:
The .327 offers more 'real-world' energy than the .357 Mag., (at least in my test), better penetration and one more shot per gun load. It does all this with substantially less recoil and noticeably less muzzle blast than the .357 Mag.
The cartridge ultimately won the NRA Publications's prestigious Golden Bullseye Award for "Ammo of the Year" (2009).
First introduced by Federal Cartridge company, the .327 Federal Magnum is an attempt to improve on the .32 H&R Magnum introduced in 1984. Like the .32 H&R Magnum, the .327 Federal Magnum is a lengthened, magnum version of the original .32 S&W cartridge, which dates back to 1878. The .32 S&W was a black powder cartridge developed by the Union Metallic Cartridge Company (UMC) with a case length of 0.61 in. (15 mm), and developed a velocity of around 700 ft/s (215 m/s). In 1896, the .32 S&W Long was introduced, which had a case length of 0.920 in (23.4 mm) and generated slightly higher velocities. The introduction of the .32 H&R Magnum nearly a century later increased the case length to 1.075 in (27.3 mm) and increased pressures from 15,000 psi to 21,000 CUP, giving velocities of approximately 1,200 ft/s (370 m/s). However, the .32 H&R Magnum cartridge failed to attract much interest from gun owners.
Based on the .32 H&R Magnum, but with a 1/8" longer case, a strengthened web at the base of the case, thicker case walls, and different heat-treatment and metallurgy, the .327 Federal Magnum can be loaded to much higher pressure levels (45,000 psi) than its predecessor (21,000 CUP). The .327's actual bullet diameter is .312 in, or 7.92 mm, and achieves velocities up to 1,400 ft/s (430 m/s) with 100-grain (6.5 g) bullets (420 m/s and 6.5 g), and up to 1,300 ft/s (400 m/s) with 115-grain (7.5 g) bullets (390 m/s and 7.5 g), when fired from the 3 1/16" (78 mm) barreled Ruger SP101 revolver.
With its strengthened case and increased pressure ceiling, the .327 Federal Magnum reaches the velocity levels of the .357 Magnum, if not the same power, with velocities of up to 1400 ft/s (420 m/s) from the 3 1/16" barrel of the first-edition Ruger SP101. Since the .327 Federal Magnum still shares all case dimensions, excluding length, with the .32 S&W, .32 S&W Long, and .32 H&R Magnum, revolvers chambered for the .327 Federal Magnum can safely chamber and fire these shorter cartridges as well.
While felt recoil exceeds that of the .32 H&R magnum, revolvers in .327 Federal Magnum are much easier to control than equivalent models chambered in .357 Magnum. Comparing the two calibers, Chuck Hawks says, "There is no doubt that, for most shooters, the .357 Mag. produces uncomfortable recoil and muzzle blast. ATK recoil figures for the .327 Mag. show free recoil energies of 3.08 ft·lbf (4.18 J). for the 85 grain JHP factory load, 5.62 ft·lbf (7.62 J) for the 115 grain JHP load and 5.58 ft·lbf (7.57 J) for the 100 grain SP load. For comparison, ATK figures are 1.46 ft·lbf (1.98 J) for the 85 grain .32 H&R Mag. load and 7.22 ft·lbf (9.79 J) for the 125 grain .357 Mag. load."
Revolvers in .327 Federal Magnum were initially offered by Charter Arms, Taurus, Ruger, and Freedom Arms. The stainless steel Ruger SP101 was originally selected as the development platform for the new cartridge. Freedom Arms made a single-action design, as did U.S. Fire Arms with its 8-shot Sparrowhawk. Ruger offered the double-action 6-shot SP101 and 7-shot GP100, and the full-sized single-action 8-shot Blackhawk, revolvers chambered in .327 Federal Magnum. A version of the Ruger SP101 with a 3 1/16" barrel chambered in the .327 Federal Magnum was released in January 2008. Ruger, U.S. Firearms, and Freedom Arms discontinued these models by the end of 2013. Smith & Wesson's Model 632 has also been discontinued.
In late 2014, Ruger introduced the smaller-framed Ruger Single-Seven, a 7-shot single-action .327 Federal Magnum revolver based on the Single-Six. In March, 2015, Ruger re-introduced the SP101 in .327 Federal Magnum. The current version of the SP101 features fully adjustable sights and a longer 4.2" (107mm) barrel. In September 2015, Ruger also introduced the LCR in .327 Federal Magnum, a double-action only, six-shot revolver with a polymer subframe.
In early 2017, Henry Repeating Arms announced production of four new lever-action long guns (a rifle and a carbine, each available with its receiver manufactured from either steel or hardened brass), with shipping scheduled to begin in March. Firearms author Chuck Hawks suggests that lever-action carbines in .327 Mag. will make "excellent, fun to shoot centerfire rifles for hunting javelina, jackrabbit and coyote"; he also notes that revolvers with 6" to 8" barrels and adjustable sights "would be excellent hunting handguns for varmints and small predators, as well as offering flat shooting protection from two-legged predators in the field."
The .327 Federal Magnum provides performance similar to the high-velocity rifle loadings of the old .32-20 Winchester, though these velocities are achieved in a much shorter revolver barrel, thanks to a much higher pressure ceiling for the .327.
Another similar cartridge is the .30 Carbine, which has been offered in Ruger's single-action Blackhawk revolver line since 1968. The .30 Carbine was essentially the same ballistically as the .32 Winchester Self Loading, which was itself basically a rimless .32-20. However, the .327 Federal Magnum has a higher maximum pressure ceiling (45,000 psi) than the .30 Carbine (40,000 psi).
Custom gunsmiths working with Ruger and Freedom Arms have offered conversions of single-action .32 H&R Single Six and Freedom Arms revolvers to .327 Federal. Test results from the long barreled guns showed even higher velocities than the .30 Carbine, along with excellent accuracy.
In April 2008, Guns & Ammo magazine's Patrick Sweeney reviewed the Ruger SP101 in .327 Federal Magnum and had this to say:
[A] .32 [Gold Dot bullet] of 115 grains going 1,300 fps is going to perform very much like a 9 mm 115-grain Gold Dot going 1,300 fps. Ballistic testing of the .327 showed it to be superior to a .38 snubbie. I got more gel penetration with the .327 (15 inches) than the .38 [Special] (12-plus inches) and greater expansion as well....
[Out of over] a dozen different 115-grain 9mm loads, only two delivered more velocity than the .327 Federal Magnum did. And in both instances, those 9mm loads did so only out of the five-inch-barreled pistol, not the compact 9mm....
If you want more than the .327 delivers, you have to go to the .357 Magnum, and having done so you will pay mightily for it. An SP101 in .357 delivers a 125-grain JHP at more than 1,300 fps, but you get only five shots and muzzle blast and recoil that could make a brass monkey flinch. With the .327 Federal Magnum you get much more than a 9mm or .38 Special in the same gun; you get six shots instead of five, and you get it at much less recoil than the .357.
Shooting Times magazine's Dick Metcalf had this to say about the .327 Mag. in the Ruger SP101 revolver (weight: 28 oz (0.79 kg)):
From a 3 1/16-inch revolver, the 100-grain Soft Point .327 Magnum load develops 100 fps more velocity than a 125-grain .357 Magnum from a four-inch revolver, and delivers only 35 ft/lbs less energy. The recoil of the .327 Magnum 85-grain Personal Defense load is less than half the recoil of a 125-grain .357 Magnum.
Subjected to the standard FBI protocol tests for effectiveness through barriers, the 115-grain .327 Magnum load reaches 15 inches in bare gelatin, 16 inches through heavy clothing, 16 inches through plywood, 14.5 inches through wallboard, 13 inches through auto glass, and 20 inches through single-layer vehicle body steel—all with substantial bullet upset ranging from .40 caliber (steel) to .60 caliber (auto glass)....
There is nothing "small" about the performance of this deceptively diminutive-looking round. Hard-hitting and entirely comfortable to fire, the .327 Magnum should be very appealing to anyone seeking high effectiveness and moderate recoil in a compact defense arm—especially those who want a handgun all responsible members of a family can readily learn to use effectively. And, should Ruger decide also to chamber it in sporting-configuration revolvers such as the Single-Six, it will also be a fine recreational shooter and small-game hunting tool.
In the Jan-Feb 2009 issue of American Handgunner magazine, John Taffin reviewed the .327 Federal Magnum in a Charter Arms Patriot revolver (6-shot, 2.2" barrel):
[T]he .327 Federal Magnum turns the .32 into a real powerhouse even when chambered in a short-barreled, small-framed, self-defense revolver....
In the Patriot Federal's original loading of a 115 grain Gold Dot JHP clocks out at more than 1,200 fps and even in the 21 ounce Patriot produces rather stiff recoil and considerable muzzle blast. For those who can ignore the muzzle blast and recoil the power is certainly there, however for normal self-defense use Federal now offers a Low Recoil load utilizing the 85-grain JHP they load in the .32 Magnum....
For those who definitely cannot handle recoil, the S&W Long 100 grain wad cutter round clocks out at just fewer than 700 fps and could be the best choice for self-defense.