M-16/AR-15 operating mechanism

[Throatwarbler_Mangrove]

Never mind.

[Mogle]

@MichaelEmouse

Or perhaps there’s a good reason to do it and I just don’t know enough about MGs.

I would guess that it was to add some redundancy to the procedure, by pulling the trigger you notice if you forgot to swipe the rounds while you still have a barrel in the weapon and it is pointed in a safe direction.