What is the most common firearm type used in US mass shootings?
Executive summary
Handguns are the single most common firearm type present in U.S. mass shootings, even as semi‑automatic “assault” rifles are disproportionately represented among the deadliest incidents (handguns: most common) [1][2][3]. Many mass shootings involve more than one firearm type, complicating simple causal claims about any single weapon category (multiple types commonly present) [1].
1. Frequency vs. headline impact: handguns dominate the counts
Across multiple datasets and peer‑reviewed analysis, handguns appear more often than rifles or shotguns in mass‑shooting events: a recent academic study found handguns to be the most common firearm present in publicly targeted fatal mass shootings (handguns most common) [1], and aggregate compilations such as Statista likewise list handguns as the most common weapon in U.S. mass shootings (handguns most common) [2]. Broader crime data also show handguns are the dominant firearm in homicides and in guns recovered at crime scenes, reinforcing that handguns are the most frequently used firearm type across a range of violent incidents (handguns common in homicides and crime scenes) [4][3].
2. Why rifles get oversized attention despite lower frequency
Rifles—especially semi‑automatic “assault” style rifles—tend to be overrepresented in media coverage because they figure in some of the deadliest and most publicized massacres, including Las Vegas, Sandy Hook, Orlando, and Uvalde, which skews public perception of how often particular weapons are used (assault weapons in deadliest shootings) [3]. Advocacy groups also emphasize that assault‑style rifles and high‑capacity magazines produce higher casualty counts when used, a point used to argue for reinstating assault‑weapons bans (assault weapons linked to higher casualties; policy calls) [5][6].
3. Lethality and context: multiple types and magazine capacity matter
Researchers caution that many fatal public mass shootings involve multiple firearm types in one incident, so attributing lethality solely to one gun class is misleading (multiple types often present) [1]. Studies have also found that the presence of assault weapons or high‑capacity magazines in some episodes is associated with higher numbers of injuries and deaths compared to incidents without them, indicating that magazine capacity and firearm design can amplify harm even if the weapon type is less frequent overall (AWs associated with increased injuries/deaths; large‑capacity magazines a common thread) [1][7].
4. Data sources, definitions, and why counts vary
Different trackers and studies use different definitions of “mass shooting” and different methods for classifying weapon types; databases such as the Violence Project and the National Institute of Justice compile firearm‑level details across decades, while the Gun Violence Archive provides near‑real‑time tallies—these methodological differences produce variation in reported shares for handguns, rifles, and mixed incidents (Violence Project and NIJ databases; GVA tracking) [8][9]. Even academic work notes category coding complications—events can include multiple firearms, and definitions of “assault weapon” vary—so raw tallies must be interpreted in light of classification choices (categories not mutually exclusive; definitional issues) [1].
5. Competing narratives and policy implications
Two consistent narratives emerge from the sources: one emphasizes frequency—handguns are the most commonly present firearm in mass shootings and in broader homicide data (handguns most common) [1][4]—while the other emphasizes impact—assault‑style rifles, though less frequent, appear in many of the deadliest attacks and are focal points for policy proposals to ban or restrict such weapons and magazines (assault weapons in deadliest attacks; policy advocacy) [3][5][6]. Both are supported by data cited in the reporting, and both have political and advocacy stakes: public safety researchers point to limiting lethality factors, while gun‑rights advocates warn about focusing on weapon classes rather than broader risk factors.
6. What this means for public understanding
The clearest, evidence‑based answer is that handguns are the most common firearm type used in U.S. mass shootings, but the most consequential policy conversations hinge on lethality drivers—assault‑style rifles and high‑capacity magazines—that amplify casualties even if they appear in fewer incidents (handguns most common; AWs amplify casualties) [1][3][7]. Any sober policy response requires recognizing both facts: frequency (handguns) and disproportionate lethality in certain high‑fatality events (assault rifles and magazines), while acknowledging that data sources and definitions differ across studies (data and definitional limits) [8][10].