In the next several weeks we will see new gun legislation proposed in both the House of Representatives (sponsored by Rep. Diana DeGette and others) and the Senate (sponsored by Sen. Dianne Feinstein and others). Both bills will call for restrictions on the sale of high capacity magazines.
For the thousands of Americans who die each year by gun suicide and gun accidents, these bills will have little effect—one bullet is enough to kill. There is ample evidence, however, to suggest that an effective ban on high-capacity magazines will reduce the number of deaths in gun homicides, especially in mass shooting scenarios.
A seven-year-long study of gunshot victims observed an increasing incidence of gunshot victims who had been shot multiple times. The proportion of gunshot victims with two or more gunshot wounds grew from 26% in the early 80s to 43% by 1990. Over the same span of years, semiautomatic handguns like the Beretta 92 and Glock 17 were replacing the .38 and .357 caliber revolvers that had been the most popular handguns in the United States in the preceding decade. The ammunition capacity in a fully-loaded handgun rose from typically six rounds to typically 15 rounds, and shooters exploited that advantage, shooting their victims multiple times and increasing the likelihood of fatal injury.
Parents Against Gun Violence researchers have identified 37 mass shooting incidents (excluding robberies and armed confrontations) involving more than 6 victims in the United States since 1945. In 35 of 37, the perpetrators carried semiautomatic weapons. In 33 of 37, the perpetrators carried magazines with a capacity greater than 10 rounds. In the recent mass shootings in Tucson, Aurora, and Newtown, the perpetrators sought out inordinately large magazines, including the 100-round drum magazine James Holmes used to shoot 70 people in a movie theater. These mass murderers clearly believe that a higher-capacity magazine will equate to more fatalities.
Opponents of the high-capacity magazine ban will point out that smaller capacity magazines can be rapidly exchanged, and will argue that such a ban will not slow or hinder a mass shooter. Online videos show expert shooters removing an empty magazine and replacing it with a fully loaded magazine with dazzling speed. Let’s remember, though, that these videos are impressive precisely because the reloading skills depicted are remarkably rare—it takes years of practice to achieve such proficiency, and the perpetrators of most mass shootings are young men with limited experience. There are cowboy trick shooters who can operate a single-action revolver or lever-action rifle with astonishing speed—but Annie Oakley doesn’t fit the profile of a mass shooter. We’re not seeking laws to stop Wild Bill; we’re seeking laws to stop Jared Loughner.
Indeed, in three instances, unarmed civilians have overpowered and disarmed a mass shooter during the momentary pause for a reload. (The smaller the magazine capacity, the more frequently the shooter must pause to reload, creating opportunities for potential victims to either take cover or fight back.)
We believe that, if mass murderers are unable to attain high-capacity magazines, the severity of their attacks will be reduced. Killers might still shoot people, but we believe they will be unable to shoot so many people so easily.
The question we should be asking now is not: “Are high capacity magazines especially dangerous?” (the answer is “yes”) but rather, “Will the currently proposed bans meaningfully reduce the availability of high capacity magazines?” A major flaw of the 1994 assault weapons ban is that it grandfathered in millions of guns and magazines that were purchased before the ban. In the months preceding the ban, demand for high capacity magazines soared, and manufacturers obliged, flooding the market with 20- and 30-round magazines. Unlike guns, magazines are usually not serialized, and require no specific record of custody. In many states, you could walk into a gun shop today with cash, and walk out with several 30-round magazines, without showing your ID or completing any paperwork. During the 1994-2004 ban, privately owned magazines were sold from one individual to another at gun shows and among acquaintances. It was more difficult and expensive to buy a high-capacity magazine during the decade of the ban, but only slightly so.
The full language of the new legislation is not yet available, but Sen. Feinstein and Rep. D
eGette have indicated that they will seek also to ban the private transfer of high-capacity magazines from one individual to another. (If you already own a 15-round magazine, you may legally keep it, but you can’t sell it to anyone else.) This is an improvement on the 94 assault weapons ban, but we believe additional measures could more effectively curb the aftermarket sale of existing high-capacity magazines. Here’s how:
First, proceed with the proposed ban on the sale of new magazines with a capacity greater than ten rounds of ammunition. Also ban the transfer of existing magazines (with more than 10-rounds capacity) from one owner to another. Illegal transfer of a high-capacity magazine should bear a serious penalty.
Second, organize a nationwide buyback program for high capacity magazines. People who currently own them will have the opportunity for remuneration, which will otherwise be lost when private transfers are banned. A nationwide magazine buyback will reduce the overall number of high-capacity magazines in the country.
Third, require that all owners of high capacity magazines who choose to keep them must register them, by taking them to a law enforcement agency where they will be engraved with a serial number corresponding to a record of ownership in a national database. A registration fee will be collected for each magazine, to offset the costs to law-enforcement agencies.
 Webster, Daniel W., ScD, MPH, Howard R. Champion, FRCS (Edin), Patricia S. Gainer, JD, MPA, and Leon Sykes, MD. “Epidemiologic Changes in Gunshot Wounds in Washington D.C., 1983-1990,” Archives of Surgery, Vol. 127, No. 6, pp. 694-698.
 These are the1993 LIRR shooting perpetrated by Colin Ferguson, the 1998 school shooting perpetrated by Kipland Kinkel, and the 2011 Tucson shooting perpetrated by Jared Loughner.