Current Rifle Cartridges
.300 Remington Ultra Magnum, aka .300 RUM
The .300 Remington Ultra Magnum
(30 Caliber) was introduced in 1999
as one of the (now) 4 Remington Ultra
Magnum, joining the .338" and .375" and
later the 7mm Remington Ultra Magnums
in 2001.
All the Ultra Magnums are based  on the
.404" Jeffery case blown out and necked
down to except their different projectile
The .300 Remington Ultra Magnum
delivers 18 % more energy then the
.300 Weatherby Magnum and 27% more
the .300 Winchester Magnum.
With velocities up to over 3,500 Feet per
Second  and energy over 4,300 Foot
pounds per square inch nd  projectiles
from 150 to 220 grains in weight, this
is an excellent long range hunting cartridge.
Above Picture on the right for size comparison:
Left to Right
7mm, .300, .338 and .375 Remington Ultra Magnums
Far Right:
.404 Jeffery, parent cartridge of the other 4 cartridges.