Weatherby has traditionally designed and built ultra-high velocity cartridges with unique case designs-belted magnums with a double-radius shoulder. This is seen in all of the existing Weatherby cartridges until now. The Mark V 6 lug standard action has been one of our best-kept secrets for years. The goal of the 6.5 WBY RPM was initially based around maximizing the potential of this great lightweight action. Setting out to produce the best backcountry rifle and cartridge combination ever it was a project not taken lightly. At our core Weatherby prides itself in ballistic superiority. The rebated rim helps achieve the desired velocity and energy we were looking for while remaining compatible with our 6 lug action. The 6.5 WBY RPM packs a punch and is capable of being chambered in Weatherby