Skip to main content

Weatherby .338 RPM: First Look

The legacy company releases their 16th cartridge in 77 years of business, introducing the .338 RPM.

Weatherby .338 RPM: First Look

Photo Courtesy of Weatherby

Built using the popular 6.5 Weatherby RPM as its parent case, the new .338 WBY. RPM. RPM combines the traditional, fire-breathing power of Weatherby components with modern ballistic technologies. The new magnum cartridge sends a heavy-for-caliber bullet at more than 2,800 fps for maximum terminal performance on big and dangerous game.

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 RPM has been purpose built to fire out of the smaller, lighter Mark V 6-lug action. The Rebated Precision Magnum family is unique compared to Weatherby’s traditional cartridges because it is a non-belted, non-venturi shoulder case with a rebated rim. Out of the gate Weatherby will be shipping four offerings in .338 WBY RPM that are in stock now and loaded with either 185- and 225-grain options with projectiles from Barnes, Hornady and Nosler.

Photo courtesy of Weatherby

“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-pound 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.”

Photo courtesy of Weatherby

Initially, the .338 WBY. RPM will be available in only select rifle offerings withing the Mark V line. Most notably, the entire Backcountry 2.0 family of rifles—with reduced-length barrels—are being chambered in the new round. During testing, our team ran the new cartridge out to 500 on the range in the Backcountry 2.0 and Backcountry 2.0 Ti Carbon, with 18- and 20-inch barrels respectively. Accuracy was, as expected, great. Most impressively, though, the recoil was not only manageable from the large cartridge, but also comfortable. For the backcountry hunter in pursuit of larger Western game, this cartridge is it.

What’s more, the company is accommodating southpaw shooters, as the 6-lug action is now being offered in a left-hand model. All of the Backcountry rifles feature left-hand options in select caliber options that includes the .338 WBY RPM.

Photo courtesy of Weatherby

.338 WBY. RPM Rifle Offerings

  • Backcountry 2.0:18-inch barrel, 5.5 lbs
  • Backcountry 2.0 Ti:18-inch barrel, 5.0 lbs
  • Backcountry 2.0 Carbon:20-inch barrel, 5.7 lbs
  • Backcountry 2.0 Ti Carbon:20-inch barrel, 5.2 lbs
  • Accumark:24-inch barrel, 7.3 lbs
  • CarbonmarkL:24-inch barrel, 7 lbs

Current Magazine Cover

Don't Miss

The Essentials Gear Box.

Our editors have hand-picked these essential pieces of gear to make you a more successful hunter when you hit the game trails this season.

Learn More

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

Recent Videos

Petersen's Hunting Magazine Covers Print and Tablet Versions

GET THE MAGAZINE Subscribe & Save.

Digital Now Included!


Give a Gift   |   Subscriber Services


Buy Digital Single Issues

Magazine App Logo

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Petersen's Hunting App

Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Get the top Petersen's Hunting stories delivered right to your inbox.

Phone Icon

Get Digital Access.

All Petersen's Hunting subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now

Enjoying What You're Reading?

Get a Full Year
of Guns & Ammo
& Digital Access.

Offer only for new subscribers.

Subscribe Now