^ In the mil-spec format, if the has fallen, the safety will not move. The safety selector should only move when the hammer has been cocked. This thread describes it well:
I just pulled out a rifle from the safe that I havent fired in a long time; a simple bone-stock Colt 6920. I was dry firing it and noticed that I could move it into safe with the hammer uncocked. Strange. I swapped the safety, along with the detent and spring, with another Colt safety as well...
www.m4carbine.net
and CalGuns Forum member "Cokebottle" describes the functionality of the FCG in his post (below) in this old CalGuns thread:
California gun discussion, Discuss guns with other California gun owners
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