[3] The .300 Win Mag is extremely versatile and has been adopted by a wide range of users including big game hunters, target shooters, military units, and law enforcement departments.

The .300 Win Mag is capable of delivering better long-range performance with heavier, large ballistic coefficient projectiles than any other standard and short length .30 caliber cartridge.

Military and law enforcement departments have also adopted the cartridge as a long-range sniper round, intended to be used for shots at longer ranges than the .308 Winchester.

The .30 Newton saw limited commercial success, however, and the .300 H&H was too long for the standard length Mauser and Springfield rifle actions of the time, barring substantial modifications.

The larger manufacturers soon noticed Weatherby's standard length magnum case, and in due time followed suit.

The popular .30 caliber's omission from that lineup prompted a response by the shooting community and Winchester's competition.

[8] The .300 Winchester Magnum's broad availability in popular rifles such as the Winchester Model 70, Ruger M77, Remington Model 700 and Weatherby Mark V, together with the wide availability of ammunition from a number of manufacturers, made the cartridge a popular choice among hunters and competitive shooters the world over.

The larger dimensions of the .300 Win Mag compared to the .308 Norma Magnum and .30-338 Winchester Magnum cartridges ensures that rifles chambered in such rounds can readily be rechambered to the .300 Win Mag, though the shorter neck of the longer round necessitates comparable bullets must be seated more deeply in the case.

(Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) have provided specifications for the .300 Winchester Magnum cartridge.

(Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings the .300 Winchester Magnum can handle up to 430.00 MPa (62,366 psi) Pmax piezo pressure.

[11] Capable of stabilizing bullets weights ranging from 110 to 220 grains, the .300 Winchester Magnum happens to be a very versatile cartridge for different purposes and conditions including big game hunting, bench rest shooting and military applications.

Although the 150 grain bullet may have a lower ballistic coefficient than heavier alternatives, this is compensated by its high velocities which extend its maximum point blank range making it suitable for light skinned big game such as deer and sheep, up to considerable distances.

The 180 and 185 grain bullets are also considered the most versatile, with a muzzle velocity of 2950 fps from average factory loads.

[12][13] Due to its high ballistic coefficients, the heavier bullets are usually preferred by long range shooters being extremely efficient in bucking wind as well as carrying downrange energy capable take down game of any size in America and Europe.

Subsequently, Remington has made low-recoil rounds called "Managed-Recoil" available for the .300 Win Mag, which recoil less while providing performance similar to the .30-06 Springfield.

Due to its flat trajectory and high kinetic energy, the cartridge is a favored round for big game worldwide, and for ranged shots and mountain hunting.

[16][13] It is often used when hunting the members of the ungulate family such as Dall sheep, mule deer, elk, and moose; being popular cartridge among hunters for these big game species.

165 and 168-grain bullets also offer a flat trajectory with higher ballistic coefficients, which retain accuracy and kinetic energy over distance.

This load offers a balance between flat trajectory, ballistic coefficient, and energy, allowing large-size big game animals such as elk and moose to be killed at considerable distances.

[23] The .300 Win Mag sees use in long-range benchrest shooting competitions and has been adopted by law enforcement marksmen and by a few specific branches of the U.S. Military for use by snipers.

This ammunition was developed as a .300 Winchester Magnum Match Product Improvement (PIP) and uses the 220 gr (14.26 g) Sierra MatchKing Hollow Point Boat Tail (HPBT) very-low-drag bullet fired at a nominal muzzle velocity of 2,850 ft/s plus or minus 50 ft/s (869 m/s ± 15.2 m/s).

According to the U.S. Navy this ammunition should increase the maximum effective range of .300 Winchester Magnum sniper rifle systems to 1,500 yards (1,370 m), decrease wind deflection on bullets in flight and use Hodgdon H1000, a reduced muzzle flash propellant that remains temperature stable across an operational temperature range of −25 °F to +165 °F (−32 °C to 74 °C).

[24][25][26] The 3.55 in (90.2 mm) long MK 248 MOD 1 or alike ammunition is not offered commercially, since it exceeds SAAMI standards for overall length and maximum chamber pressure.

[27] According to JBM Ballistics,[28] using the 0.310 G7 ballistic coefficient provided by Bryan Litz, and a Weapon Employment Zone (WEZ) analysis of the XM2010 rifle with various .300 Winchester Magnum ammunition types by Bryan Litz, the MK 248 MOD 1 .300 Winchester Magnum cartridge, when fired at its nominal muzzle velocity of 869 m/s (2,850 ft/s), should have 1,286 to 1,289 m (1,406 to 1,410 yd) supersonic range under International Standard Atmosphere conditions at sea level (air density ρ = 1.225 kg/m3).

[29][30] In January 2014, the U.S. Department of Defense annual testing report found that the older A191 or MK 248 Mod 0 .300 Winchester Magnum service round loaded with aerodynamically less efficient 190 gr (12.32 g) Sierra MatchKing Hollow Point Boat Tail (HPBT) bullets (0.270 G7 ballistic coefficient provided by Bryan Litz) fired from the XM2010 demonstrated adequate performance and lethality.

[31][30] Several companies, among them HS precision, Kimber and Remington manufacture rifles chambered for the .300 Winchester Magnum specifically targeted at law enforcement agencies.