I"m looking for someone to answer a question regarding the dimensions of the various Kimber 8400 receivers? Is there only one receiver with common dimensions (including feed ramp design) for the various magnum cartridges this rifle was offered in from the factory? I'd like to build a .300 Win Mag rifle from a 8400 receiver, they are not as easy to find in .300 WM as the "short fat" (.270/.300/.325 WSM) rifles and instead of limiting myself to one originally built as a .300 Win Mag, I'd like to use what is more readily available to build this project.