re: Rebuilt a K98, should be safe to fire?

So the internal diameter of the bore is 8mm (0.323")? The chamber looks to be longer than the 8x57. If you have a kinetic hammer you can pull the bullet from the loaded ammo, insert the bullet in the chamber and measure the distance fo the lands. That might give some idea of the overall length of the loaded round. I can't find a video of how I do it (read it in a Nosler manual MANY years ago) so I'll describe it. Other methods require you to have the gun's brass or a special tool. Insert a rod into the bore from the muzzle until the rod touches the closed bolt face. Make a mark on the rod at the muzzle. Insert a bullet into the chamber until the bullet is at the lands. While the bullet's in the lands, insert the rod into the bore. Make a mark on the rod at the muzzle. Use a micrometer to measure the distance between the two marks and you have the overall length for the round w/ the bullet at the lands.

Using your micrometer, what's the diameter of the shot brass at the case head? If it's a Weatherby chamber, it seems like the fired brass would fireform to the larger diameter of a Weatherby. I'd also think the fireformed brass would show some sort of belt at the case head if the gun has a Weatherby chamber. The fireformed brass looks too long at the start of its shoulder to be a 8-06 Improved chamber. OTOH, the German 8 X 68 mm S has a longer body than the 30-06 so might it be a possible candidate for the chamber?

If someone on the OB will start a "Go Fund Me" page to buy Scoob some Cerrosafe and a lead ladle, I'll contribute. I'll even provide a "How to Use Cerrosafe" video .
Other than a propane heater, all you need is some Cerrosafe and a lead ladle.

Keep us updated. I'm dying to find out the actual chamber.