Dear Lager Larcenist,
Switching the barrel while keeping the breech block (because of availabilities / qualities) is something all of us with bad barrels (notice the plural) have considered. The practicalities of doing this, however, without machine shop equipment & skills, are a steep hill to climb, especially considering marring of surfaces must not happen, while considerable force is utilized, on lengths of soft steel.
Bad barrels aren't drilled out. They are pulled out.
With shipping etc., LW barrel blanks fetch close to what one generally pays for a complete second hand German springer. The blanks still need to be cut, prepped, and the riskier than risky barrel switch performed. It almost makes more sense to buy another gun altogether. Although getting a HW .22 cal that shoots well might take years with this approach.
