It's very true that guns do not kill. A gun is an inanimate object. It requires animation to have it function as a killing machine. But why does it happen? I don't know that it's possible for someone to twist the aspect of a gun to make it kill -- but a gun does have a purpose.

* You could wire it up so that it fires at a target when another part of your rigged system is animated, but this still falls to the person setting up the trap as the guilty party.

* I recall an old, extremely enjoyable, comedy flick with Cary Grant (as Newspaper Editor Walter Burns) and Rosalind Russell (as Star Reporter Hildy Johnson) called "His Girl Friday," in which a convicted murderer, John Qualen (as condemned man Earl Williams), was offered an interview with the press (Russell), in which the idea of "production for use" was used as a defense angle:

Williams: “He [some soap-box talker] said everything -- should be made use of.”
Hildy: “It makes quite a bit of sense, doesn't it? ...Now, look, Earl. When you found yourself with that gun in your hand -- and that policeman coming at you -- what did you think about? ...You must have thought of something... Could it have been, uh, 'production for use'? ...What's a gun for Earl?”
Williams: “A gun? ...Why to shoot, of course.”
Hildy: “Oh. Maybe that's why you used it.”
Williams: “Maybe.”
Hildy: “Seems reasonable?”
Williams: “Yes -- yes it is. You see, I've never had a gun in my hand before... That's what a gun's for, isn't it? Maybe that's why.”
Hildy: “Sure it is.”
Williams: “Yes, that's what I thought of. ‘Production for use.’ Why, it's simple isn't it?”
Hildy: “Very simple.”
Williams: “There's -- nothing crazy about that, is there?”
Hildy: “Nope. Nothing at all.”

The gun was bought for protection, and it was designed to kill, therefore it was properly used... Cleverly interesting.

Regardless, I don't think the issue here is that one political system kills more than another, but rather that one political system entices to kill more than another. The purpose of a particular system, and what steps people take to ensure the system remains functioning, are what truly matters. As you said:
People are able to pervert any religion, economic system, or political philosophy into an EXCUSE to kill people, and have. There have been acts of terrorism sponsored by capitalist, communist and socialist economic systems.

Ergo:
Governments don’t kill. Politicians do.

It likely trickles down to the average Joe from there...

It all boils down to people. After all, we’re the brains behind the system, right? What is the government's 'production for use'?

Perhaps I've strayed in this, but it feels like an accurate assessment,
Dan