Say you had a number 1 take-off barrel off a 458......could it be rethreaded for a mauser action? Say the barrel is 22" long and you wanted to end up at 20" while retaining the front sight and the quarter rib......can the quarter rib be removed, the barrel cut at the breech, rethreaded, rechambered and then the quarter rib re-installed? Would it be worth the trouble?

You have dowel and screw holes for the rib. The rib is fitted to the barrels contour utilizing the cylinder portion of the barrel. Moving everything forward 2 inches would likely be more trouble than it is worth.

Malm

A whole lot of work on a $25 barrel, but it can be done if you want to pay the price.