When we talk about gun rights and gun control, there’s often very little understanding among some about firearms in any appreciable way. They’re not gun people, which is fine, but they still feel like they have the ability to speak on the subject with some degree of authority.

What’s funny is that many know they aren’t experts on firearms, yet still are sure they know better than those who do.

I ran into a prime example, recently, in a letter to the editor from Newport, Oregon.

“I know next to nothing about guns, having never owned or even fired one,” the author starts. He then writes, “But it seems clear to me that there’s a distinct line separating those guns with practical uses — hunting, putting down seriously sick or injured animals, target shooting, self-defense — and those guns designed for only one purpose: killing people. ”

He then goes on to say that those designed for killing people should be unavailable for private ownership and pretends that “well regulated” in the Second Amendment means precisely what he wants it to mean regardless of the rest of the text.

So, about that “distinct line separating those guns with practical uses,” which he acknowledges includes self-defense, and those only for killing people. I’m curious just where he thinks that line is.

I ask because self-defense is an action that may well require you to take a life. At a minimum, it requires having the ability to respond to lethal force with a level of force capable of killing someone.

So just how do you differentiate between one meant to kill someone and one meant to be used in self-defense? Where in the copious experience the author posses does one find that “distinct line” between these weapons that are used for one versus the other?

Round capacity is a function of a magazine, not the weapon itself. Further, how many rounds does it take to murder someone? How many may be needed to protect yourself?

Take this piece by Heritage Foundation’s Amy Swearer, who is responding to articles she wrote being cited by gun control groups as supporting magazine round restrictions.

Left out of that article—but still included in Heritage’s database and highlighted on the @DailyDGU Twitter account—was an Aug. 19 example of defensive gun use in Williamsport, Pennsylvania, by a concealed carry permit holder who fired 18 rounds while defending himself against an armed robber.

A cursory review of Heritage’s database reveals this is far from the only confrontation that didn’t make it into the monthly “highlight reel,” despite involving more than 10 rounds fired in self-defense.

In the March article, for example, we declined to highlight a Feb. 22 case in Richmond, Kentucky, in which a man fired at least 19 rounds using two firearms during a shootout with an intruder who had just killed the man’s daughter.

That same month, a gun owner in Washington state told reporters that he fired an entire magazine of ammunition at a gunman, providing covering fire for two wounded sheriff’s deputies during a shootout and likely saving their lives.

So, if this author is arguing round capacity as the determining factor in whether a gun is used for self-defense or homicide, these instances–and this is far from a comprehensive list, to say the least–should put that to bed.

Or maybe he thinks semi-automatics are the danger. If so, it should be noted that all of these are also semi-automatic firearms, as are a number where fewer than 10 rounds were fired. The semi-automatic action is more than a century old at this point, and they’ve been used for self-defense for pretty much all of that time.

Yet the author makes this statement with absolute authority, as if he actually knows what he’s talking about.

He’s not alone, though. This is common. People who know nothing about guns or their use will speak with absolute authority on the topic, then dismiss and ridicule those of us who know the harsh reality.