A picture showing the differences and blank weights [unchambered] between the Bartlein Remington Varmint #13, and the custom contours of the 1.250" and 1.350" Senderos we stock. The 1.350" shank is recommended for actions that have a 1.125" tenon. The longer 4" shanks on the Senderos we order are better suited for the longer length case of the 338 Lapua, 338 Norma and the 33XC.