Is military experience a valid indicator of firearm and shooting know how? It might be but probably not. As always the proven, demonstrated skill of the individual is what matters. Prior service does not.
T. Mark Graham, gunsmith for Arizona Response Systems, LLC, sums this up nicely.
I fail to see where military service is a prerequisite for intelligent evaluation of firearms design and employment. Some of the stupidest things I’ve seen were from Special Forces Weapons Sergeants, such as stomping on an M60 cocking handle and shearing it off and the receiver in an excessive, failed effort to clear a malfunction. I ended up fixing the problem with my bare hand.
My friend worked at a gun store. He would frequently be asked what supersecret ninja-commando unit he was in that gave him the “credibility” to sell a gun. His response was, “Dude, I’m just the guy behind the counter.”