.375 Ruger (9.5 x 65.5mm)
Type Rifle
Place of origin USA
Production history
Designer Ruger
Designed 2007
Parent case Unique
Case type Rimless, bottleneck
Bullet diameter .375 in. (9.5mm)
Neck diameter .405 in (Bad rounding hereScript error mm)
Shoulder diameter .515 in (Bad rounding hereScript error mm)
Base diameter .532 in (Bad rounding hereScript error mm)
Rim diameter .532 in (Bad rounding hereScript error mm)
Rim thickness .050 in (Bad rounding hereScript error mm)
Case length 2.580 in (Bad rounding hereScript error mm)
Overall length 3.340 in (Bad rounding hereScript error mm)
Case capacity 99 gr H2O (6.435 cm³)
Rifling twist 1-12" (304.8 mm)
Primer type Large rifle
Maximum pressure 62,000 psi (Bad rounding hereScript error MPa)
Ballistic performance
Bullet weight/type Velocity Energy
270 gr (Bad rounding hereScript error g) SP2,840 ft/s (Bad rounding hereScript error m/s)4,835 ft·lbf (Bad rounding hereScript error J)
300 gr (Bad rounding hereScript error g) DGS2,660 ft/s (Bad rounding hereScript error m/s)4,713 ft·lbf (Bad rounding hereScript error J)
300 gr (Bad rounding hereScript error g) DGX2,660 ft/s (Bad rounding hereScript error m/s)4,713 ft·lbf (Bad rounding hereScript error J)
Test barrel length: 23
Source(s): Hornady[1]

The .375 Ruger (9.5 x 65.5mm) is a rimless, standard-length rifle cartridge designed for the hunting of large dangerous game. It is designed to provide an increase in performance over the .375 H&H cartridge, yet to be chambered in a standard length action rifle. The cartridge was designed by Hornady and Ruger in partnership and released commercially in 2007 and chambered in the Ruger Hawkeye African and the Ruger Hawkeye Alaskan rifles.[2]

Design & SpecificationsEdit

The .375 Ruger uses a unique case designed by Hornady and Ruger. The case is of a rimless design having the base and rim diameter of .532 in (Bad rounding hereScript error mm) which is the same diameter of the belt on belted magnum cases based on the .300 H&H Magnum and .375 H&H Magnum. This allows the cartridge to have a greater case capacity than a belted magnum case given cases of equal length. As Ruger intended the cartridge to be chambered in standard length bolt action rifles[2] the case length was kept to 2.580 in (Bad rounding hereScript error mm) which is only .04 in (Bad rounding hereScript error mm) longer than the .270 Winchester case. The maximum overall length of the cartridge is 3.340 in (Bad rounding hereScript error mm) which is similar to the maximum overall length to standard length cartridges such as the .338 Winchester Magnum or the .30-06 Springfield. Unlike Remington Ultra Magnum cartridges, the Ruger Magnums can be chambered in standard length bolt action rifles. This allowed Ruger to chamber the cartridge without extensively redesigning their M77 rifle platform to adopt them to the new Ruger cartridge.

While the .375 H&H Magnum is longer than the .375 Ruger, the latter cartridge has a greater case capacity than the Holland & Holland cartridge. This is due to the .375 H&H Magnum having a long tapered body while the .375 Ruger follows modern cartridge designs in that it has very little taper and a sharper shoulder. The case capacity of the .375 Ruger is 99.0 gr. of water (6.43 cm3) while the .375 H&H Magnum has a case capacity of 95.3 gr. of water (6.19 cm3), an increase of 4%.

.375 Ruger SAAMI cartridge dimensions - all dimensions in inches (mm)

Cartridge standards for the .375 Ruger was issued by SAAMI in June 2007. SAAMI recommends a 6 groove barrel having a bore Ø of .366 in (Bad rounding hereScript error mm) and a groove Ø of .376 in (Bad rounding hereScript error mm) with a groove width of .115 in (Bad rounding hereScript error mm). The recommended rate of twist is one revolution in 12 in (Script error mm). Recommended maximum pressure for the cartridge is 62,000 psi (Bad rounding hereScript error bar).

Performance Edit

Currently Hornady and Double Tap manufacture ammunition for the .375 Ruger cartridge. The Hornady superformace ammunition drives a Hornady 270 gr (Bad rounding hereScript error g) SP-RP bullet at 2,840 ft/s (Bad rounding hereScript error m/s) and the 300 gr (Bad rounding hereScript error g) DGS and DGX bullets at 2,660 ft/s (Bad rounding hereScript error m/s). The Double Tap gets 2825fps - 4700 ft./lbs. with a 270 grain Barnes TSX from a 23" bbl. Ruger 77 African. The.375 Ruger's slightly greater case capacity, and the "short fat" cartridge efficiency lead to increases in the neighbourhood of 150 fps over the H&H cartridge. Their capabilities remain essentially comparable.


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  2. 2.0 2.1 Anderson, Petter (23 January 2009), "375 Ruger – en värdig arvtagare?" (in Swedish), Jakt & Jägare,
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