The 6.5 WBY RPM (Rebated Precision Magnum) is based on the lengthened version of the .284 Winchester. The large body diameter, low body taper, and 35-degree shoulder mean that case capacity is greatly increased, leading to higher velocities.
CARTRIDGE SPECS
Bullet Diameter: .264 (6.5mm)
Common Reference: 6.5mm Caliber
Max Case Length: 2.57”
Production Start: 2019
The .270 Weatherby Magnum cartridge was developed by Roy Weatherby in 1943 and was the first belted magnum to be offered to the public when he open his business in 1945.
CARTRIDGE SPECS
Bullet Diameter: .277 (7mm)
Common Reference: 270 Caliber
Max Case Length: 2.549”
Developed: 1943
Production Start: 1945