(CNN) Vermont Gov. Phil Scott on Wednesday signed sweeping gun control measures -- including limits on the size of magazines -- that the Legislature passed last month after contentious debate.

The measures:

-- Raise the minimum age for gun buyers to 21;

-- Ban bump stocks, which allow semiautomatic weapons to fire more rapidly;

-- Require all gun transactions to be facilitated by a licensed dealer who would perform background checks, except for law enforcement or military members acting within their duties, or for gun transfers between immediate family members;

-- Limit rifle magazines to 10 rounds.

State residents will be permitted to keep larger-capacity magazines they already own.

As he signed the measures, Scott, a Republican, called himself a Second Amendment supporter who owns guns and has hunted his whole life. But he said continued mass shootings in the United States and a recently foiled school shooting plot at Fair Haven Union High School in Vermont "forced me to do some soul searching."

"I want every student and every school, every mom and dad, every victim of violence in any form to know that today we stand together as we take steps towards making our community safer for all of us," Scott said.

There were boos as well as cheers from people watching Scott as he made his remarks outside the Vermont Capitol.

The Legislature's approval of the measures came as other states also consider gun safety restrictions since a mass shooting in February that left 17 people dead at Marjory Stoneman Douglas High School in Parkland, Florida.

Scott had backed the new firearms safety legislation, which came after police foiled the plot at Fair Haven shortly after the Parkland shooting.