Hey Judson!! Glad to see you.. while you are half right the pressure in a rifle exists in 2 references- peak pressure and time(duration). Thus you can increase velocity by incrasing pressures(usually) or by maintaining the peak pressure for a long time reference. This equates to a push of the same pressure on the bullet's base but for a longer distance down the bore. This is the reason the big magnums use large quantities of relatively slow burning powders.. ssooooo - more case capacity equals more velocity- at the same pressures,,,all else being equal..of course. The Lott is about .350" longer than a 458winmag. This is just enough to generate the 458 mag velocities at the same pressures and avoid compressed powder charges, common in the 458WinMag.. The Watts as listed in AmmoGuide is about .005 inches longer than the Lott and is thus about .350-.400 inches longer than the 458 Winchester. Also all the belted mag rounds(most anyway) are derivatives of the 375 case, to one extent or another. Whether I'd bother with the trouble of a wildcat is based on the rifles price and how badly I needed such a cannon.