Just some additional information....My 1950 carbine has the same trigger, but will not do this. Parts are identical.
I do notice that the trigger guard on the 1950 does not allow the trigger to move forward, sort of capturing the forward movement of the trigger.

The MC does not "capture" forward movement of the trigger. AND, I notice some side to side play in the trigger. Now this one has a different TG, in that it is held in place by a wood screw to the stock at the rear. Remove the screw, pivot the TG aside to get at the rear action screw. There seems to be more of a gap in this TG at the front than on the 1950 model.

BTW...trigger guard is serialed same as the rifle.

Will see if photos can be taken.