A 26" barrel that is .600" at the muzzle is typically about .200" larger at the neck. In the picture that barrel looks to be pretty close to that. A Krieger #2 sporter contour is .600" at the muzzle and .800" at the neck. Krieger won't make a 30 caliber barrel any smaller than a #5 contour in stainless steel. A #5 contour is .700" at the muzzle and .900" at the neck. They will make a 30 caliber #2 contour from chromoly but they won't flute it. They won't even flute a #5 in chromoly or stainless. To get a 30 caliber barrel fluted by Krieger it's going to have to be about an inch in diameter at the neck. They measure the neck 6" forward of the breech.
I think your friend gave you incorrect information.