"I've done more sales in the week after the 19th than I have the whole year," says Zimmerman, who launched SelwayArmory.com in 2009.
At Lady Liberty Gunsmithing LLC in Atlantic City, N.J., a customer called last week asking if a pistol he wanted was available. When he was told there was only one left, he drove more than two hours from Newark, N.J., to buy it that same day.
"People want guns now even more than ever," says Guy Petinga II, whose father opened the store above his home in 1996.
Others saw demand immediately after the shooting.
Bullet Blocker, which makes bulletproof vests, briefcases and insert panels, saw sales of its children's backpacks suddenly jump.
"That's how I found out about the tragedy. I saw the sales rise and then turned on CNN," says Elmar Uy, vice president of business operations at the Billerica, Mass., company.
Bullet Blocker has sold about 50 to 100 bulletproof backpacks a day since the shooting, up from about 10 to 15 in a regular week. The children's backpacks, which are designed to be used as shields, cost over $200 each.
"I've never seen numbers like this before," says Uy.
Follow Joseph Pisani at http://twitter.com/josephpisani
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.