I think the conversion was done on a pre-Ithica LaFever which is a great gun but not a strong enough canidate for a double rifle conversion.Lots of people seem to be getting into building double rifles on shot gun actions, I have seen some sleeved Stevens 311 up here and not all shot guns have the strength for rifles so think before you build. Too much work is involved in the conversion for you to blow one up on the reproof testing. Also it is not worth your life or body parts. If (IMHO) you do not have a gun where you can determine the proof pressures and insure that your conversion are well below (30% or more per square inch) that then find another gun to work with. Guns are cheep compaired to your life or law suits!