Cant really answer that for you ssj, I'm not into the No4 so don't have a great deal of knowledge on them, i only have one as i feel i have too, a 1943 Savage (Stevens :) ) Mk1* & a close relative, a No1 MkVI
https://www.milsurps.com/images/impo...3no4main-1.jpg
https://www.milsurps.com/images/impo.../mkvione-1.jpg