Most BSA knives have BSA shields which this does not. It is a common "bare head" jack and they were made by every knife company and the shield was also used by most companies so true ID will never be known. Bare head refers to the fact there is no back bolster.
It looks like an old Case or Barlow the federal shield was common on a lot of different brands The brand was more than likely on the blade, the shields were more of a place for owners initials to be engraved.There were quite a few different styles of shields.Here is a link to see some of the styles of shields GEC SHIELDS | Great Eastern Cutlery