The last entry of A GOOD REASON discussed a gun control law that worked: the 1934 National Firearms Act. The NFA placed a hefty tax on machine guns (and other highly lethal weapons) and required owners of such weapons to register with the US government. It was a success. Before the NFA, gangsters sometimes robbed banks and fought each other — and law enforcement officers – with machine guns. After 1934, criminals stopped using machine guns.
The experience of the NFA does not, of course, prove that a ban on all privately-owned guns would reduce gun crimes. In fact, a total ban on guns might lead to more gun crimes, since criminals could rob and burglarize in the comfortable knowledge that they were the only ones with guns.
Nevertheless, the NFA did succeed in reducing the “lethal firepower” used by criminals. Instead of toting machine guns, criminals carried less lethal weaponry.
Could a limit on magazine capacity replicate that success, and further reduce the “lethal firepower” used by criminals? (A magazine is a sleeve of bullets attached to a rifle or handgun. They range in capacity, 
from 3 bullets to over 150 bullets.)
A law limiting “magazine capacity” to, say, 10 rounds might be particularly effective in saving lives when the criminal is a mass murderer, determined to kill as many people as possible. A killer with a 10-round magazine in his rifle can shoot fewer people than a killer with a 100-round magazine in his rifle. The killer with a 10-round magazine has a weapon with less lethal firepower.
Even if the 10-round killer is carrying 9 more magazines in his backpack, he still has less lethal firepower than the 100-rounder, because the 10-rounder has to pause to reload as each magazine is emptied. Those pauses to reload make a difference. It is during those moments that people can escape, or possibly overpower the shooter. Which has happened more than once:
- In 2011 in Tucson, Arizona, Jared Loughner used a Glock pistol with a 33-round magazine, which he fired in 15 seconds, killing six people and severely wounding US Congresswoman Gabrielle Giffords. He was wrestled to the ground and subdued when his magazine was empty and he stopped to try to reload.
- In 1998, Thurston High School student Kipland Kinkel, in Springfield, Oregon, emptied his 50-round rifle magazine, killing 2 students and wounding 24 others, but was tackled as he paused to reload.
- In 1993, Colin Ferguson, opened fire on a Long Island Rail Road train, killing six and wounding nineteen. He fired off two 15 round magazines, but as he paused to reload with a third magazine, passengers overpowered him.
It is true that a limit on magazine capacities may not make much of a dent in the overall murder rate in the US, since “mass shootings” (defined as 3 or more fatalities) make up less than 1% of the US murders. But the numbers are still horrific. According to the Violence Policy Center, since 1980, 503 people were killed and 495 wounded in 55 mass shootings using high-capacity magazines. (And these numbers were probably an under-count, according to the Violence Policy Center, because magazine capacity is not always reported.) Mass shootings will happen again. Why shouldn’t we pass a law that could reduce the number of people killed?
Another counter-argument is that such a restriction has been tried before, with mixed results. In 1994 the federal government banned “assault rifles” and magazine capacities over 10 bullets in the “Federal Assault Weapons Ban” (officially, the “Public Safety and Recreational Firearms Use Protection Act”). But the 1994 law was weak. It contained, for example, a “grandfather” exception on guns and ammunition lawfully owned on the date of the law, which meant that there were plenty of large-capacity magazines around. Moreover, the law contained a “sunset” provision, meaning it automatically expired in 2004. Consequently, it was probably too short-lived to have a significant impact. (Although there were positive signs. In Virginia, the number of high-capacity magazines recovered by police was beginning to drop, only to rise again after the law expired in 2004.)
The 1934 National Firearms Act showed that raising the cost of highly lethal weaponry can cause criminals to use less lethal weaponry, and it seems to me that that lesson could be applied to high-capacity magazines. A law imposing a 10-bullet magazine capacity may keep criminals away from high-capacity magazines, just as the 1934 law steered criminals away from machine guns.