Are Semiautomatic Weapons with Large Capacity Magazines and/or other Military-Style Features More Criminal and/or Dangerous?

I would like to know the answer to the question asked in the title of this post, so I was interested to see that Christopher Koper has recently published an article in the Journal of Urban Health: “Criminal Use of Assault Weapons and High-Capacity Semiautomatic Firearms: an Updated Examination of Local and National Sources.”

I thought I could assign the paper in my Sociology of Guns seminar in Spring 2018. But I have to confess that I have not read the entire article yet. In fact, I did not make it through the article’s introduction.


I got hung up on a passage which bothered me so much that I couldn’t read on.

Koper writes: “Semiautomatic weapons with LCMs and/or other military-style features . . . tend to produce more lethal and injurious outcomes when used in gun violence.” I did not realize that had been established in the scholarly literature (hence my being excited to read this article).

OK, so I check the citations for this statement. The citations should support the statement being made. Citation #2? Koper’s work assessing the effect of the federal assault weapons ban for the National Institute of Justice: “An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994-2003.” This work suggested that there was no clear effect of the AWB, but that there might have been an effect if it was in place longer and with fewer loopholes.

I do not know all of the scholarly literature on the topic — which is why I was excited to see Koper’s new article — but I do know that Gary Kleck has presented evidence suggesting that large capacity magazines do NOT produce more lethal outcomes (at least in mass shootings). The intentions of the person doing the murdering are more important.

This is in line with the paper by Koper on the relative hazards of revolvers vs. semi-auto pistols that I just discussed in my last post. Revolvers were nearly 60% more deadly than semi-autos in that study. Again suggesting that the intention of a person to do lethal harm to another may be key to understanding different outcomes, rather than the mechanism used (at least when comparing different types of firearms; remember: don’t bring a knife to a gunfight).

Which brings me to Citation #17, given by Koper to help support the assertion that “Semiautomatic weapons with LCMs and/or other military-style features . . . tend to produce more lethal and injurious outcomes when used in gun violence.”

Citation #17 is to the same study comparing the injuriousness and lethality of semi-auto pistols and revolvers that I discussed in my last post!!!

And you know from having read my last post that Koper’s earlier study that he cites here actually shows revolvers to be equally injurious to semi-auto pistols, AND MUCH MORE LETHAL.

I am still planning to read the rest of the article and possibly assign it in my class in the spring. I’m interested to see what it says and what my students think it says, which are often two different things.

Which is sadly all too true with much of the gun (violence) research used to advocate for public policies regulating guns and gun owners.



  1. “Results show that the use of assault weapons is not related to more victims or fatalities than other types of guns.” (Blau et al., “Guns, Laws and Public Shootings in the United States”, published in 2016)

    Liked by 1 person

      • Interesting that high cap mags and handguns have independent effects. I am interested to see the models. I can’t access the whole article through my library so have requested a copy from the author

        Liked by 1 person

      • This is where my stats weakness comes in.

        Are “high cap mags” and “handguns” really independent variables?

        With handgun being equivalent to “semi-automatic handgun” versus “revolver,” it would seem to matter if the pistol had a standard capacity greater or less than 10 rounds and was used with its factory-standard magazine containing more or less than 10 rounds. As opposed to the VT shooting where the shooter had extended, almost double capacity, mags for his pistols.

        I guess I’m assuming that most mass shooters aren’t using the smaller “concealed carry” pistols with single stack mags, or buying extended single stack mags for them, but rather the typical 15 round guns. If that’s the case, then the “high capacity” number is going to skew higher not because the mags are a “selected tool of choice” but because pretty much every modern handgun, which is the selected tool, comes with one right out of the box.

        I suppose a mag limit law could just require 10 rounds, but even if the >10 mags magically disappeared, since handguns would remain the gun of choice for all crime, I would assume that “10 round mags” would quickly match the prior numbers for “high capacity magazines” as they would simply be the “mag in the gun” same as before, not specifically sought out.


      • Here’s what the Montreal Coroner Teresa Sourour said in her report after Montreal massacre (1989):

        “The issue of firearms control has intentionally not been addressed. With the unlimited ammunition and time that Marc Lépine had available to him, he would probably have been able to achieve similar results even with a conventional hunting weapon, which itself is readily accessible.”

        Click to access montreal-coroners-report.pdf


      • Wait.

        So the authors aren’t saying any causation, but merely correlation?(question mark added for uncertainty)

        If they are saying there is just a correlation, than that could easily be reconciled with Kleck’s work.


  2. I just read the abstract and after the many times ‘assault’ showed up figured it was just another magazine or self loading rifle ban thing and stopped reading.

    Liked by 1 person

  3. One could bore one’s self to death with the statistics. I think the question is a philosophical one as well as a number-crunching one. If the Vegas shooter was not so well-armed and able to spray bullets at a crowd so easily, perhaps there would have been fewer casualties? Imagine if Charles Whitman had a couple modern ARs up in the UT library tower instead of that slower bolt action rifle.

    So if I were a policy-maker, I would want to know if mass shooters, albeit a small portion of the total shootings, could be significantly impeded with an AR regulation such as making them National Firearms Act items. What is the cost-benefit ratio to society of having these so readily available? And I would tell 2A purists to save their arguments for someone else. Ever since Vegas, I go back to something I wrote in 2015:

    “…There are legitimate questions as to why a private citizen should own high capacity (i.e., 30-50 round magazine autoloading) weapons primarily developed for the battlefield with no strings attached ( I find the difference between semiautomatic and full auto capability a distinction without a difference in the present context). Indeed, the Swiss and Israelis, who have allowed citizens to keep arms for their universal “militias”, have increasingly put restrictions on them. That said, efforts at eliminating or regulating “assault rifles” have been introduced long after the horses left the barn. Civilian, semi-automatic versions of the M-16 and AK-47, which with their various sister and successor rifles have become iconic in some circles, were introduced half a century or more ago and the vast majority never make the news. No serious thought was given to restricting civilian versions of modern military rifles before they became popular; once a very porous ban (of dubious utility) was finally proposed in the nineties, it became an “out of my cold, dead hands” controversy. Further, the ban made no real sense as it left millions in circulation and finally, the ban was often based more on appearance than function. Even millions more are now out there and although they are used in a few high profile slaughters (Aurora, Newtown, etc,), they are largely not the weapon of choice for street crime shootings. Furthermore, they are ideal home defense weapons (blowing a hole in the side of your neighbor’s house notwithstanding) for the same reason the Marines want them for close quarter combat. That all said, if lunatics continue to use them to deliver high velocity carnage to schools, theatres, and fire departments, some sort of regulation is inevitable on public safety grounds (and is likely permissible under Heller). Constitutional issues aside, we let just about everyone drive (and some do a bad job of it, leading to more than 30,000 traffic deaths a year). We don’t let everybody drive a Freightliner. It seems to me that lacking the will and legal authority for an “Australian Solution” perhaps an amendment of the 1934 National Firearms Act, act to make these restricted in a manner similar to full auto weapons (or somewhere halfway) is a good idea.”

    Liked by 1 person

    • He did have an M1 carbine and a pump-action .35 cal hunting rifle. As I understand it most of the fatalities were caused by aimed fire in the first 15 minutes or so with the scoped bolt gun, not unaimed-ish rapid fire with the others. After that amount of time the crowd below started suppressing him so he could only pop up and spray shots.

      Liked by 1 person

      • Yeah. I went and checked. From some of the personal recollections of people, apparently a lot of the fraternities provided enthusiastic fire. Toxic masculinity on display. 😉 Probably good they were shooting upwards and, I assume, their hunting rifle rounds had the range to clear the suburbs.


  4. Reblogged this on and commented:
    The most dangerous things are:
    (A) Hollywood
    (B) Low IQ individuals
    (C) News media hype for ratings
    (D) The “deer in the headlights” individuals
    (E) Persons with out of control emotions

    That’s what is dangerous about semi-automatic firearms with large capacities (more than one round of ammunition) and/or military style (can of black spray paint = assault weapon) firearms.


  5. Not having read it (as he sets himself up for embarrassment) , it looks like another study where a bit of firearms (history) knowledge would add some light.

    It would be interesting to finally get a definition of “high-capacity” beyond “more than I think guns should hold.” When the Colt AR first went on sale in ’64 (for $189.50 MSRP!) it often shipped with a 5 round magazine that was simply a 20 rd mag with a block to meet some states hunting regs, but factory 20 round magazines were standard. 30 round mags entered the market I think simultaneously with their military adoption in the early 70’s.

    Is the magazine the gun was -designed to hold- “high-capacity” or “normal capacity?” If “high,” compared to what non-arbitrary number? The 6 of a traditional revolver? The 7+1 of a 1911? The 10+1 of a Savage 1907? The 13+1 of a 1935 Browning Hi-Power? The 14+1 of the Smith Mdl 59 (circa 1971)? The 17+1 of the Glock 17 of ’82?

    Beyond the arbitrary “high capacity magazine” usage, there seems to be the usual conflation between the modern “assault weapon” marketing term and “semi-automatic” to capture all other rifles, shotguns, and handguns. We are talking about century old technology both in terms of existence -and- use in crime, yet treating both as if they are novel and definitive.

    Using Vegas as an example, the NYT just put out a timeline, their analysis of the gunshot recordings show 17 second and longer (37 sec?) intervals between bursts (can’t watch the video at work to see how many shots per burst and haven’t yet seen a total shots fired count). A mag change of a 20 or 30 round standard magazine takes maybe a couple seconds if you are slow. If he was using 50 or 100 round mags or drums (which are harder to manipulate, for me anyway and often less reliable) he’s only upping his on board firepower by 2 or 3 times, yet he had time to spare for 5 or 6 “standard capacity” mag changes between each burst. He also had, as many mass shooters do, multiple weapons. Even with 10 round magazines, with 23 rifles lined up ready to go, he has 230 rounds on tap before needing to change a mag firing into that packed crowd.

    I’m unconvinced that mag size limits/confiscations, even if possible in practice, would have any real effect on mass shootings. Shooters tend to have as much time as they want, to do what they want, until someone shows up to stop them. The “well, maybe someone could tackle ’em during the mag switch” is more hope than likelihood.

    The only scenario where I can see any possible positive effect is maybe for things like drive-by’s or single mag dump assaults, but those are not common, involve criminal actors unlikely to be impacted by any new laws, and might run into the prior “revolver versus semi-auto” lethality issues. In any event, it’s not enough justification for massive legal or policy changes in my opinion.


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