Are slam fires common in an AR?

[Sinclair]

When I was much younger and uninformed about firearms I put a round in the chamber and dropped the bolt and bang it fired. Wasn't ever really sure if it was a slam fire or some other malfunction in the fire control group. I have had people say an AR will not slam fire but it seems others have experienced it.

The problem with you guys building from a "kit" of parts acquired from various venders is that cross platform compatibility can be hit or miss. A genuine slam fire happens when the inertia of the firing pin is sufficient to activate the primer. Many years ago, I built a FAL from parts I acquired from various surplus houses. I had two sets, one legal and the other illegal. Because I had been told the the FAL was notorious for slam fires, so one day I disassembled the trigger group and installed the illegal parts. Did the two round test and yes the primer was dented, but the second round did not fire. After many attempts, I concluded that maybe there were other causes for the apparent slam fires that others had. Actually, the dent did not appear be any larger than from the firing pin alone with the legal parts.

My Father had a Colt 1911 that had been accurized and if you released the hold back latch and let the slide go forward under spring pressure on a chambered round, it would go full auto firing several rounds before it stopped. Bad gunsmithing! The jar of the unopposed slide slamming to a stop caused the hammer to slip of off the sear. Exciting, but not actually a slam fire. What I am saying is that IF an AR can or does seem to slam fire, the problem might be in the trigger group being out of whack.

Since there are so many heavy thinkers on this forum, I wanted to inject my 2 cents worth as something for you all to think about.