Just a point, there was another "M16" issued with full auto capability! the first ones issued to us Marines in Vietnam, the XM16E1, a true POS. Because I was attached not organic, I was able to keep my M14 (which did have a selector) from 67 when the Mattey Mattel first showed up to spring 69, when I was forced to turn it in for the POS.
I was a rifleman before I went into the corps, so I really liked the M14. In 67 and the first half of 68 getting over run was a rather regular happening. The M14 made a much better baseball bat than the POS.
One thing I learned, is that once the NVA got through the wire, a Semi-auto weapon became automatic! The second time I was wounded was in a position that was getting overrun and a satchel charge took me and part of the trench line out. I was one of the lucky ones.
Inside the home I prefer a shotgun, in my case the double barrel 12ga hammer gun next to my bed, or the Benelli M4 in my open safe, cruiser ready.
I do like pistol caliber carbines, but more for fun than serious social work.
I gave my FNH SCAR Mk 16 to my son in law, so for my at home light carbine I presently have a SIG Carbine/ACOG setup for the immediate neighborhood. I have sighted in and ranged all the major trees/bushes and house corners around my home.
If I go on an adventure that would require serious hardware, I would fall back on my M1A/M14. Old dog and such.
Full auto is fun, but not very practical for me.
Go figure.
Fred