BELLEVUE, WI -- In the wake of these latest deadly shootings, firing ranges in Northeast Wisconsin have been extra busy.
And some guns are having a hard time staying on the shelves.
NBC26 spoke with several gun shops from Green Bay, to the Fox Cities--all reporting a recent surge in gun sales, and sign-ups for firearm safety courses.
Along with that, there are more new faces at the firing ranges.
At Family Shooting Academy, in Bellevue, "business is up a lot," says owner Mike Shea. "Our training is up, range usage is up, gun sales are up."
One gun--the controversial AR-15 assault rifle--is particularly hot.
"We're selling them as fast as we can receive them at this point," says Shea.
It's a spike that Shea says is also bringing in more college-aged, and single, female shooters.
"[There are] a lot of 'I've never owned a gun before. I've never owned a handgun before,'" says Shea, "coming in to buy handguns."
Shea says personal safety in the wake of a growing fear of domestic terror is a driving factor.
"We're seeing an increase in terror attacks in the U.S.," says Shea, "from the most recent one in California, to the Boston Marathon bombing."
Those calling for gun reform say steps--like increased background checks, a ban on gun sales to those on the 'anti-terrorist no-fly list,' and banning assault rifles--would help curb gun violence.
"Congress must act to ensure that no one who is a suspected terrorist can buy guns anywhere in America," says Democratic Presidential candidate Hillary Clinton, just days after the shooting in San Bernardino.
But gun owner, and registered nurse, Anthony Pijanowski, says those who wish to do harm will always find a way.
"People get stabbed every day," says Pijanowski, "people get beat up, and there's way more violence than just gun shooting."
In the meantime, Pijanowski says he's putting personal safety in his own hands.
Attacks, like San Bernardino, are often followed by a spike in gun sales.
FBI stats show background checks for gun purchases grew 39 percent in the days following the Sandy Hook massacre in December of 2012, in which Connecticut State Police say an AR-15 assault rifle was used by shooter Adam Lanza to kill 20 children, and six adults.