|.375 Remington Ultra Magnum|
|Place of origin||United States|
|Parent case||.300 Remington Ultra Magnum|
|Case type||Beltless, rebated-rim, bottleneck|
|Bullet diameter||.375 in (9.5 mm)|
|Shoulder diameter||.5250 in (13.34 mm)|
|Base diameter||.5500 in (13.97 mm)|
|Overall length||3.600 in (91.4 mm)|
|Primer type||Large rifle magnum|
|Maximum pressure||65,000 psi (450 MPa)|
|Maximum CUP||< !-- Ballistic performance --> CUP|
|Test barrel length: 26|
Source(s): Alliant Powder
It is a beltless, rebated rim cartridge created by necking up the .300 Remington Ultra Magnum case to .375 caliber with no other changes. Factory loadings are less powerful than handloads for the cartridge. Remington factory loads push a 300 grain (19 g) bullet at 2760 ft/s (840 m/s), producing 5070 ft·lbf (6.88 kJ) of energy. A handloader can increase the muzzle velocity of a 300gr bullet to 3321 ft/s (900 m/s), and develop 5800 ft·lbf (7.9 kJ).
The intended use of this cartridge includes hunting large, thick-skinned game. It is powerful enough to kill any land animal and, with its high velocity, can do so at fairly long ranges. Such performance comes at the price of a heavy recoil: in a sporting-weight rifle of ~8 lb (3.6 kg), this cartridge can produce a fierce 80 ft·lbf (108 J) of recoil (approximately 3.5 times that of a .30-06.)
Currently, there are no production rifles in this chambering (Savage & Remington previously did so.) Remington, DoubleTap and Nosler are the only sources of factory ammunition. Loading dies and reloading data are readily available to the handloader. Double Tap loads to the specifications attributed to handloader limits.