Weatherby Debuts 25 WBY RPM Cartridge

Weatherby is expanding its RPM cartridge family with the launch of the 25 WBY RPM (Rebated Precision Magnum), a fast-twist quarter-bore designed to push modern, high-BC bullets at true magnum velocities without the bulk of a traditional magnum rifle.

The new 25 RPM is engineered around Weatherby’s Mark V six-lug action. It uses a refined RPM case with a rebated rim, minimal body taper, and a 35-degree shoulder. The goal is efficiency. More usable case capacity, consistent performance, and an overall length that supports today’s long, heavy-for-caliber projectiles.

With a 1:7.5 twist rate, the 25 RPM is optimized for bullets many legacy .25-caliber cartridges struggle to stabilize. Weatherby says the cartridge can drive a 133-grain Berger at roughly 3,000 fps. This offers flatter trajectories and stronger downrange energy than familiar options like the .25-06, .257 Roberts, or 25 Creedmoor.

According to CEO Adam Weatherby, the company chose not to tinker with Roy Weatherby’s classic .257 Weatherby Magnum. Instead, the 25 RPM was designed to complement it. Specifically tuned for the heavier bullets now common in long-range hunting and precision shooting.

Versatility is part of the pitch. While the cartridge shines with long, sleek bullets, it can also push lighter projectiles past 3,300 fps, making it a viable all-around option for hunters chasing everything from open-country game to longer-range opportunities.

At launch, factory ammo will include loads from Berger, Barnes, Hornady, and Hammer, with brass available for reloaders. The cartridge will be chambered in both Weatherby Mark V and Model 307 rifles, giving shooters multiple entry points into the platform.

Whether the 25 WBY RPM becomes the new standard for modern quarter-bores remains to be seen. But on paper, Weatherby is clearly aiming to bring the .25 caliber into the fast-twist era. Learn more here!

*** Buy and Sell on GunsAmerica! ***