New for September 2022.
RPM = Rebated Precision Magnum
One Cartridge, not a Box:  338 Weatherby RPM by Weatherby, factory loaded using new Weatherby brass cases with “WEATHERBY / 338 WBY RPM /” Head-Stamp and loaded with a 225 grain Interlock JSP (Jacketed Soft Point) projectile.
   
History of the 338 Weatherby RPM Cartridge:
The 338 Weatherby RPM (Rebated Precision Magnum was introduced in 2022, and is  Weatherby’s  sixteenth cartridge to be accepted into the SAAMI in Weatherby’s 77 years of business as of this writing in September, 2022.
With loadings of 185 to 225 grains, velocities up to 3,100 feet per second producing  energy of up to almost 4,000 foot pounds per squire inch.
All in a 5 pound standard action rifle! Ouch, that would make your shoulder hurt.