For 2026, Weatherby has extended its cartridge line with the addition of the .25 Rebated Precision Magnum, the third in the series. Based on the .284 Winchester cartridge, but with an extended case length, the RPM series debuted in 2019 with the 6.5 RPM, followed with the .338 RPM. Both were designed to take advantage of the six-lug Weatherby Mark V action, in the lightweight Backcountry Ti, a sub-five pound rifle.
Quarter-bores seem to be making a strong comeback of late, first with the .25 Creedmoor garnering a good amount of attention, and now with the .25 Weatherby RPM. What we see is a cartridge with a rebated rim measuring 0.473 inches—the same as the .30-06 Springfield and .308 Winchester families—and a body diameter of 0.500 inches. The cartridge overall length stays at 3.340 inches, the same as the .30-06 and many other long-action cartridges, but it seems Weatherby has shortened the case a bit in comparison to the 6.5 RPM, presumably to ensure that the 6.5 RPM can’t be accidently chambered in a .25 RPM rifle, resulting in a tragedy when the trigger is pulled. A 35-degree shoulder handles the headspacing duties while leaving plenty of room for a healthy powder charge. But rather than just releasing another iteration of the common .25-caliber cartridges, Weatherby follows the trend of offering a cartridge which can utilize heavier projectiles than are normally associated with the quarter bores.
Where the .25-06 Remington, .257 Roberts and even Weatherby’s own .257 Magnum use a 1:10-inch twist barrel, the new .25 Weatherby is mated to a 1:7.5-inch twist barrel, allowing the use of heavier bullets with higher Ballistic Coefficient values. These heavy bullets have proven to be the best choice for long range work. Included in the mix of available ammunition for the .25 RPM is a 107-grain Hammer bullet (a lathe-turned monometal) at 3,350 fps, a 117-grain Hornady SST and 117-grain Barnes LRX at 3,150 fps, and the Berger Elite Hunter 133-grain bullet (with a G1 B.C. of 0.613) at an even 3,000 fps.
Chambered in the Weatherby 307 rifles as well as the Mark Vs, there are some great options for those hunters who wish to take the .25 caliber to a new level, with plenty of reach-out-and-touch-‘em. I can easily see where pronghorn and muley hunters might be shopping for one of these. I do believe the quarter bores have a new lease on life.
