Here is a photo of my 1907 Jeffery 404 compared with one of the new Ruger 416's The size, weight and balance are very close

The 24 inch barrel taper is not a straight one. It measures 1.26 in front of the receiver and then has a slight bell shape. At 13" it measures .855 , then another incher further toward the muzzle it has a step down to .745 and then only tapers to .725 at the muzzle

The barrel is quite a bit lighter than Rigby used on it's 416