197 Republicans – all but 10 – vote against raising minimum age to buy semi-automatic assault rifles
The Capitol Building (AFP)

Responding to the increase in mass shootings Democrats in the U.S. House of Representatives Wednesday evening voted to raise the minimum age to buy semiautomatic weapons, like the popular AR-15 style assault rifle, from 18 to 21.

The measure passed 228-199, with all but ten Republicans voting against it. Two Democrats also opposed the bill.

The measure is part of a larger gun control bill. Should it make its way to the Senate it would face stiff opposition from Republicans.

But gun safety activists say it would be "huge" if it becomes law.

“The impact would be huge. Any federal law that is an effective gun safety policy has a much broader impact than the law of any one state. Certainly, it would limit the number of people in that age range that could purchase firearms,” Allison Anderman, Giffords’ senior counsel and director of local policy, told NBC News, which adds she "pointed to data showing that people ages 18 to 24 have disproportionately higher rates of mental illness and propensity to commit violent acts."

“It makes a lot of sense to ensure they can’t buy these firearms,” Anderman said.