My intent was to suggest that it should be obvious that a belt-fed weapon, individual or crew-serviced, would be there for full-auto fire. But that brings up an interesting question, quite the opposite of the original question.
Why should a machine gun (whatever you care to call it) have a semi-automatic or select fire capability? Supposedly the policy was for the Bren gun to be used as a semi-automatic weapon "to disguise from the enemy that a machine gun is being used against them." Are machine gunners really trained to try to achieve single shots on a full-auto only weapon?
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.