'rayg' - That doesn't work with Krags.
Carbine and rifle barrels have the same taper. A Kragbarrel diameter, measured 22 inches from the closed bolt-face, ranges, approximately .651 to .655 inches, (carbine or rifle barrel). I have one model 1898 carbine barrel that measures .645" diameter at the muzzle; this .010" difference is less than the thickness of two sheets of printer paper! (BTW - My model 1899 carbine barrel measures .652" at the muzzle).
The best validation of a legitimate 22" Krag carbine barrel is a 'practiced eye' examining the quality of the front-sight base attachment - IMHO.