| .300 Norma Magnum | |
| Origin: | Sweden |
| Type: | Rifle |
| Designer: | Norma |
| Design Date: | 2012 |
| Is Si Specs: | yes |
| Parent: | .338 Norma Magnum |
| Case Type: | Rimless, bottleneck |
| Bullet: | 7.83 |
| Neck: | 8.68 |
| Shoulder: | 14.29 |
| Base: | 14.87 |
| Rim Dia: | 14.93 |
| Rim Thick: | 1.52 |
| Case Length: | 63.30 |
| Length: | 93.50 |
| Case Capacity: | 6.75 |
| Rifling: | 229 mm (1 in 9 in) |
| Max Pressure: | 440.00 |
| Pressure Method: | CIP |
| Primer: | Large rifle magnum |
| Is Si Ballistics: | no |
| Bwunit: | grain |
| Bw1: | 220 |
| Btype1: | MatchKing |
| Vel1: | 3003 |
| En1: | 4404 |
| Balsrc: | Cartridges of the World, 2012 |
The .300 Norma Magnum, also known as .300 NM or 300 Norma, is a centerfire magnum rifle cartridge developed by Swedish ammunition manufacturer Norma Precision. The .300 Norma Magnum uses a .338 Norma Magnum parent case necked down to .30 caliber, named to differentiate it from the older .308 Norma Magnum designed in 1960, and has begun to gain popularity among long-range shooters. According to the official C.I.P. (fr|Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives) rulings, the .300 Norma Magnum can handle up to 440MPa Pmax piezo pressure.
The United States Special Operations Command (USSOCOM) chose the new MK22 Advanced Sniper Rifle, which is chambered in .300 Norma Magnum (designated M1163) as well as .338 Norma Magnum.
The .300 Norma Magnum chambering is offered in these factory rifles: