I appreciate all your inputs, as I have remanded custody of said suspect firearm to a truly talented and accredited AR15 gunsmith for just a cursory FCG and whole unit inspection. I WILL say that after attempting to get this to occur WITHOUT a round in the chamber, I failed to get the hammer to fall. Seems to only do this when a round is chambered with the action locked open and after I chamber the round and select FIRE, does it occur. That being said, I am worried about the ability to move the selector to "safe" prior to even setting the action back. So... my gunsmith will approach this from two ways: Either contact Smith or just repair whatever is goofed up. I appreciate all the input here. There is a great, vast ocean of experience in this location. Thank you all.