The barrel problem appears to be to be only in the .22's. Myself and several other folks feel that the factory uses the same tool setting for both the .177 & .22 barrels when the they get indexed and drilled for the sights, with less remaining wall thickness in a .22 barrel, when the tap goes in and bottoms the .22's get an interior bulge.
roald said mine did well with the 15.something grain jsb. and superdomes werent bad