The M1919A4 and 60MM mortar was Company level . Remember though that loose weapons were everywhere , and if someone latched onto something and added it to the pile , nothing was usually said. That is how squads that were to have a single BAR sometimes had two or three . Same for pistols , Thompsons , etc.
There is a book that really lays it out you might get. i'll have to get the title and author if I can find it in all my stuff , I havn't seen it for awhile.
Chris