Nearly all SC barrels were 4-groove and virtually all were made by High Standard. 6-groove barrels, while somewhat uncommon, are by no means rare. 2-groove barrels, if they exist, are rare. The story was that High Standard was offered the initial contract to manufacture '03s, but had too much war work. Smith-Corona was hired, with HS being one of the main sub-contractors.

Regarding the so-called "Savage" barrels, there is a lot of false information on them but I don't remember the exact story.