|Place of origin||United States|
|Case type||Rebated rim, straight walled|
|Bullet diameter||.3570–.0030 in (9.068–0.076 mm)|
|Neck diameter||.378 in (9.6 mm)|
|Base diameter||.390 in (9.9 mm)|
|Rim diameter||.378 in (9.6 mm)|
|Rim thickness||.045 in (1.1 mm)|
|Case length||1.71 in (43 mm)|
|Overall length||2.25 in (57 mm)|
|Case capacity||36.5 grains (water)|
|Rifling twist||1 in 16 in (410 mm)|
|Primer type||Small Rifle|
|Test barrel length: 20 in|
The .350 Legend (9×43 mm), also called 350 LGND, is a SAAMI-standardized straight-walled hunting cartridge developed by Winchester Repeating Arms. The cartridge was designed for use in American states that have specific regulations for deer hunting with straight-walled centerfire cartridges. Winchester claims that the .350 Legend is the fastest production straight-walled hunting cartridge in the world, although some .444 Marlin and .458 Winchester Magnum loads are faster. It is designed for deer hunting out to a maximum effective range of 250 yards (230 m).
Ohio's Deer Hunting Regulations allow the use of a straight-walled rifle cartridge with a minimum caliber of .357 inches (9.1 mm). Consequently, the .350 Legend is a legal hunting rifle cartridge there.
The .350 Legend shares many characteristics with the .223 Remington, the overall cartridge length is 2.26 inches (57 mm) long with a rim diameter of .378 inches (9.6 mm), but it is not derived from the .223 Remington. Because of its similarities to the .223 Remington and 5.56 mm NATO, the .350 Legend is suitable for use in AR-15 type semiautomatic rifles, and will fit in most standard AR-15 magazines without modification.
Winchester has introduced many successful cartridges, including the .44-40 WCF (Winchester Center Fire), the .30 WCF (.30-30), the .50 BMG, the .270 Winchester, the .308 Winchester, the .243 Winchester, the .22 WMR (.22 Magnum), the Winchester Short Magnums (WSM), the .264 Winchester Magnum, .338 Winchester Magnum, the .458 Winchester Magnum and the .300 Winchester Magnum.
At the 2019 SHOT Show in Las Vegas, Nevada, the .350 Legend cartridge was introduced by Winchester Ammunition. The Sporting Arms and Ammunition Manufacturers' Institute (SAAMI), the U.S. firearms and ammunition industry’s technical standards-setting organization, announced the acceptance of the new cartridge and chamber standard on January 31, 2019.
The cartridge was developed to deliver enough energy to achieve lethal terminal effects on large deer out to 200 yd (180 m). The recoil is said to be less than a .243 Winchester. Winchester is currently offering five different loads for the new cartridge: a 150 gr (9.7 g) Deer Season XP at 2,325 ft/s (709 m/s), a 180 gr (12 g) Power-Point at 2,100 ft/s (640 m/s), a 160 gr (10 g) Power Max Bonded at 2,225 ft/s (678 m/s), a 145 gr (9.4 g) FMJ in the USA ammo line at 2,350 ft/s (720 m/s), and a Super Suppressed 255 gr (16.5 g) subsonic load at 1,060 ft/s (320 m/s).
The cartridge offers a flatter trajectory with less recoil and better terminal performance over current straight-wall cartridges while remaining compliant in most applicable states.
The .350 Legend cartridge is designed to cycle in a variety of firearm platforms, and has been shown to operate in bolt-action rifles like the Winchester XPR.
.350 Legend has no parent case. However, .350 Legend uses the same 0.378 in (9.6 mm) nominal rim diameter as .223 Remington. The .350 Legend shellcase is a new design that maximizes terminal performance while optimizing the ability to extract the cartridge from the chambers of a variety of firearms. The .350 Legend did not adapt a .223 Remington parent case in order to incorporate a slight body taper (for extraction), as well as additional shellcase length and case volume.
Winchester engineered .350 Legend hunting projectiles (such as the Extreme Point and Power-Point bullets) for use on big game out to 250 yd (230 m). These bullets were designed specifically to maximize .350 Legend cartridge performance.
The .350 Legend cartridge is engineered for deer hunters requiring a modern straight-walled cartridge. It is capable of killing hogs, deer, and coyotes. With bullet weights ranging from 125 to 280 gr (8.1 to 18.1 g), the .350 Legend is a highly versatile cartridge with many end uses.
The ability to practice cheaply with low recoil, high velocity .35 caliber (9.1 mm) rounds legal for deer hunting opens the door for many new shooters whose recoil sensitivity precludes their use of cartridges such as .450 Bushmaster or 12 gauge slug guns.
.350 Legend also addresses a rapidly growing market segment known as "straight-wall-cartridge-compliant" deer-hunting states. A growing number of states that previously restricted deer hunting to limited-range slug guns or muzzle loading firearms are now allowing rifles chambered in straight-walled centerfire cartridges.
The .350 Legend was designed for deer hunting in states that have specific regulations for straight-walled cartridges, such as Michigan, Ohio and Iowa. Illinois also allows straight-walled cartridges if used with a pistol. The pistol must be a centerfire revolver or centerfire single-shot handgun of .30 caliber or larger with a minimum barrel length of 4 inches.
Indiana is sometimes also mentioned as having laws requiring a straight walled case; however this is not correct. For example, the Indiana Department of Natural Resources (Indiana DNR) website lists most calibers above .243" (6.2 mm) as allowed on private land. But when hunting on public lands in Indiana the DNR cartridge specifications do require cartridges with a maximum case length of 1.8” and caliber of .357” or larger. The 350 Legend is specifically listed as an example of a legal cartridge by the DNR. However, bottleneck cartridges meeting these size criteria are legal as well.