.338 Remington Ultra Magnum

.338 Remington Ultra Magnum
Type	Rifle
Place of origin	USA
Production history
Designer	Remington
Designed	2000
Specifications
Parent case	.300 Remington Ultra Magnum
Case type	Beltless, rebated, bottleneck
Bullet diameter	.338 in (8.6 mm)
Neck diameter	.371 in (9.4 mm)
Shoulder diameter	.5261 in (13.36 mm)
Base diameter	.5500 in (13.97 mm)
Rim diameter	.534 in (13.6 mm)
Case length	2.760 in (70.1 mm)
Overall length	3.600 in (91.4 mm)
Case capacity	113 gr H2O (7.3 cm3)
Rifling twist	1-10 in (254 mm)
Primer type	Large rifle magnum
Maximum pressure	65,000 psi (450 MPa)
Ballistic performance
Bullet weight/type Velocity Energy 250 gr (16 g) PSP Bonded 2,860 ft/s (870 m/s) 4,540 ft·lbf (6,160 J) 250 gr (16 g) PSP A-Frame 2,860 ft/s (870 m/s) 4,540 ft·lbf (6,160 J)
Test barrel length: 26"

The .338 Remington Ultra Magnum is a .338 caliber rifle cartridge introduced by Remington Arms in 2002.

Design

It is a beltless, rebated rim cartridge based on the .300 Remington Ultra Magnum case shortened .090" and necked-up to accept a 0.338-inch (.338 caliber) bullet. The .338 Remington Ultra Magnum has a similar case capacity as the .338 Lapua Magnum and somewhat lower than that of the .338-378 Weatherby Magnum. It is one of the most powerful .338-caliber rounds in production.

Because this cartridge already operates at very high pressures (65,000 PSI), handloaders cannot realize significant velocity improvements over factory ammunition as many handloaders have done over the years with more conventional, lower pressure rounds. However, they can still tune their own loads for best precision in their specific rifles, as with any other cartridge.

See also

• List of rifle cartridges
• Table of handgun and rifle cartridges
• .338 Edge

References

• .338 Remington Ultra Magnum reloading data at accuratepowder.com BROKEN
• .338 Remington Ultra Magnum case diagram