Using the 6.5 WBY RPM (Rebated Precision Magnum) launched in 2019 as a parent case, Weatherby is now officially launching the new 338 WBY RPM, their 16th cartridge in 77 years of business.

Weatherby is known for ballistic superiority, touting many of the fastest cartridges available by caliber, as well as the strongest rifle action available with the Mark V Magnum 9 lug action. Like the 6.5 WBY RPM, the new 338 Weatherby RPM has been purpose built for the smaller Mark V 6 lug action. The Rebated Precision Magnum family is unique compared to Weatherby’s 14 preceding cartridges because it is a non-belted, non-venturi shoulder case with a rebated rim.

Out of the gate Weatherby will be shipping 4 offerings in 338 WBY RPM that are in-stock now.

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

To complete this system, Weatherby will be chambering the following models in the new 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