I've just finished a google search and I believe I have discovered a new m16 model from the past. I want to call it the colt 605SD because It has features of the 605 and 605 B but isn't a 605 because most have full fenced lowers and foward assist. The 605 is on a partial fenced lower with a 603 or slabside upper. Also all of the 605SD have suppressors. here are my pictures of it.
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