Weatherby 338 WBY RPM: Magnum Firepower, Built to Go Long

Few companies own a reputation for magnum performance quite like the folks at Weatherby. The company built its reputation, in part, on launching bullets at incredible speeds. Now Weatherby ups the ante once more with its new .338 WBY RPM, the company’s 16th cartridge release over its 77-year history.

.338 WBY RPM

The new .338 derives from the 6.5 WBY RPM (Rebated Precision Magnum). Launched in 2019, the 6.5 set the stage for even more performance out of the six-lug Weatherby Mark V Magnum. The .338 WBY RPM utilizes a non-belted, non-venturi shoulder case and includes a rebated rim. Weatherby will offer four different loads to start.

.338 WBY RPM Loads

Weatherby Select Plus -185-grain Barnes TTSX – muzzle velocity of 3100 fps with a 24” brl
Weatherby Select – 225-grain Hornady Interlock – muzzle velocity of 2800 fps with a 24” brl
Weatherby Select Plus – 225-grain Nosler Accubond – muzzle velocity of 2825 fps with a 24” brl
Weatherby Select Plus -225-grain Barnes TTSX – muzzle velocity of 2800 fps with a 24” brl

“Upon the launch of the 6.5 WBY RPM in 2019, we began to dream of what could be next in the RPM family,” said Adam Weatherby. “Having successfully launched a 5 lb rifle in a 6.5 caliber magnum cartridge, I began to imagine what it would be like if we had a big bore option that could fit in the same Weatherby Mark V 6 lug action. Field testing for the 338 WBY RPM began back in 2020 when my son was able to take the first animal with Weatherby’s 16th cartridge introduction on a spring bear hunt. That following fall, Brenda and I both shot elk and moose ranging from 90 yards out to 550 yards and the cartridge performed tremendously. I am truly honored to be able to carry on my grandfather’s legacy of cartridge development and rifle building. The pairing of this new cartridge with our latest rifles reminds me of one of his old slogans that said “Tomorrow’s Rifles Today.” I only wish he could be here to see the innovation and development that our amazing Sheridan-based team is able to accomplish.”

To mark the launch of the new cartridge, Weather will offer five rifles in 338 WBY RPM. The styles range across the spectrum of hunting rifles.

Weatherby Rifles in .338 WBY RPM

Backcountry 2.0 – 18” #3 Contour Steel Barrel – 5.5 lbs
Backcountry 2.0 Ti – 18” #3 Contour Steel Barrel – 5.0 lbs
Backcountry 2.0 Carbon – 20” #4 Contour BSF Carbon Barrel – 5.7 lbs
Backcountry 2.0 Ti Carbon – 20” #4 Contour BSF Carbon Barrel – 5.2 lbs
Accumark – 24” #3 Contour Steel Barrel – 7.3 lbs
Carbonmark- 24” #4 Contour BSF Carbon Barrel – 7 lbs

More New Offerings

But Weatherby isn’t stopping there. The company also announced the release of left-handed, six-lug actions. The addition includes the entire Backcountry 2.0 line, in multiple cartridges.

Left-Handed Options

240 WBY MAG
243 WIN
6.5 CM
6.5 WBY RPM
280 AI
30-06 SPR
308 WIN
338 WBY RPM

Editor’s Take

Precision shooting continues to drive cartridge development across a wide spectrum. As those skillsets grow, so too does the proliferation in long-range hunting pursuits. Stated plainly: more folks want to shoot game a longer distances than seemingly ever before. Now that style of hunting brings its detractors to be sure. But hunting, especially out West, brings its own challenges. For those required or interested in going long, cartridge development remains a hot topic.

Weatherby knows how to put performance into rifle cartridges. When the Weatherby name gets stamped on a casing, history says it brings a ton of performance. We expect nothing less from the new .338 WBY RPM.