300
RUM
The .300 Remington Ultra
Magnum, also known as the .300 Ultra Mag' or .300 RUM is a 7.62 mm (.308in.)
caliber rifle cartridge, 7.62x72mm, or .30 caliber rifle cartridge introduced
by Remington Arms in 1999. The .300 Remington Ultra Magnum is one of the
largest commercially available .30 caliber magnums currently being produced. It
is a beltless, rebated rim cartridge, capable of handling all large North
American game, as well as long-range shooting. Among commercially produced
.30-caliber rifle chamberings, the .300 Remington Ultra Magnum is second to the
.30-378 Weatherby Magnum in cartridge-case capacity.
Suggested
Use
- Deer (long range)
- Bear (long range)
- Sheep / Goat (long range)
- Moose
- Elk
- Buffalo / Bison
- Anything on four hooves
Performance
Remington ammunition for
the .300 RUM is available in three Power Levels. Power Level I duplicates the
.30-06 Springfield, Power Level II that of the .300 Winchester and Power Level
III is the full power load. Remington offers the full power (Power Level III)
.300 Remington Ultra Magnum ammunition in 150 gr (9.7 g) at 3,450 ft/s (1,050
m/s), the 180 gr (12 g) at 3,250 ft/s (990 m/s) and the 200 gr (13 g) at 3,032
ft/s (924 m/s). These are among the highest velocities attained by a .30
caliber production rifle cartridge
The .300 RUM is an
excellent long range cartridge with the ability to deliver a useful level of
energy downrange especially with the power level III ammunition.. Due to its
high velocity it exhibits less bullet drop than most other .30 caliber (7.62
mm) cartridges.
SAAMI recommends that the
barrel have a 6 groove contour with a twist rate of one revolution in 10 in
(250 mm). The barrel is to have a groove width of .115 in (2.9 mm). Bore is
given as .300 in (7.6 mm) and a groove is .308 in (7.8 mm). Maximum case overflow
capacity is 122.5 gr. of water (7.30 cm3). SAAMI recommended Maximum Average
Pressure is set at 65,000 psi (4,500 bar).
Remingtons ultra magnum
cases were made wider than the .404 Jeffery case by .006 in (0.15 mm). The
brass was made thicker so as to withstand the higher pressure of the new
cartridge as the Jeffery cartridge had a maximum average pressure rating of
3,650 bar (52,900 psi)
|