Thousands of semiautomatic, military-style rifles filter out of Garrett Streitz’s gun manufacturing business every year, and there’s no shortage of people who want to buy one.

“It’s just the modern gun,” said Streitz, who owns Alex Pro Firearms in Alexandria, Minn.

To others, they are weapons of war whose lethality was again put on grim display in a pair of attacks this month that slaughtered more than 30 people and wounded dozens more in El Paso, Texas, and Dayton, Ohio.

The latest round of bloodshed has sharpened an already roiling gun debate around the country and in Minnesota, which has included impassioned calls to revive a federal ban on assault weapons that was in force for a decade before expiring in 2004.

Since then, the nation has become awash in the guns: Estimates by researchers and trade groups hold that there are as many as 20 million assault-style rifles in the country, with more than a million being produced each year. Since the federal ban lifted in 2004, production of all types of rifles has since soared 219%.

Ask John Monson where customers first look when they walk into his Bill’s Gun Shop & Range location in Robbinsdale and he’ll point to a wall covered with more than 120 semiautomatic military-style rifles whose display is not unlike an art gallery installation.

The image underscores a key challenge to proposals to try to remove the guns from society.

“Unless they actually come and take them all, it will be 50 to 100 years before a ban on those firearms will have an overall impact,” said Monson, who also owns stores in other metro cities as well as Fargo and Hudson, Wis.

It’s all but impossible to make an exact accounting of how many semiautomatic rifles are in Americans’ hands as there is no official ledger of private ownership. The term “assault rifle” also lacks a universal definition. But Minnesota is one of a few states to define “semiautomatic military-style assault weapons” in state law, requiring that purchasers get a permit to buy them.

Minnesota’s definition covers 17 models of firearms — including popular models like the AR-15 and AK-47 — that can fire and reload a single round with one trigger squeeze. They allow for a high rate of fire because shooters don’t need to manually reload until the full magazine is empty.

Beyond target shooting, the rifles have also grown in popularity among hunters, Streitz said, adding that a common misconception is that the gun is far too powerful to be reasonably used for hunting animals like coyotes or prairie dogs.

“It’s a rifle — it’s a tool for a sportsman,” said Streitz, whose customer base includes both area hunters and local law enforcement agencies. “It just takes people like we have seen in these shootings to use that tool in the wrong way. It’s heartbreaking for all of us people who support the Second Amendment and support hunting with these style of rifles.”

Jillian Peterson, a Hamline University professor whose Violence Project think tank is studying all mass shooters in the country since 1966, said that while handguns make up a significant bulk of the data set, assault rifles are beginning to appear more frequently and are responsible for the worst of the mass killings.

“You do see more of them recently, and they tend to be deadlier,” said Peterson.

The Ohio shooter reportedly modified an AR-15-style pistol to act as a rifle and used a 100-round drum magazine to kill nine people and wound 27 others even though police were able to stop him in less than a minute.

“There is absolutely no reason why any citizen should be able to carry those types of guns,” said Joan Peterson, co-chair of the gun safety group Protect Minnesota’s Northland chapter in Duluth. “That is absolute insanity. Why? Why? Why?”

Under scrutiny amid recurrent waves of mass shootings, the gun industry has also adjusted how it refers to semiautomatic military-style rifles. In the past decade, the National Shooting Sports Foundation, a trade group, popularized the term “modern sporting rifle,” which has since been picked up by those in the industry like Streitz and Monson.

“That’s to get away from the evil black gun concept,” Monson said.

During a break between shifts delivering ice last week, Kyle Rosenquist and his co-worker Trevor Warner stopped by Bill’s Gun Shop & Range to take another look at the Smith & Wesson M&P15 rifle Rosenquist planned to buy once his background check cleared.

Rosenquist identifies as a leftist and a socialist and said his interest in firearms stemmed from target practice with friends to celebrate birthdays and bachelor’s parties. That exposure led him to rethink what he described as his traditionally liberal beliefs like supporting weapons bans.

“If you just give somebody a gun, it’s not going to unlock some murderous rage within them,” Rosenquist said.

Rosenquist is hoping to become one of the nearly 290,000 gun-permit holders in Minnesota, an all-time high reported by the state Department of Public Safety in March. The FBI last week reported that it has conducted nearly 397,000 firearm-related background checks for Minnesota through July, putting the state on pace to match or pass a record set just two years ago.

Rosenquist said he was looking for a relatively inexpensive rifle — the Robbinsdale store had models ranging from a few hundred dollars to more than $3,000. Yet Monson said the vastness of the store’s stock was in stark contrast with the aftermath of previous high-profile mass shootings and presidential election years.

“It’s different this time,” said Monson. He noted that past mass shootings have been followed by runs on gun stores by those worried about new legal restrictions. Now calls for bans and other stricter gun controls have become commonplace, producing less anxiety in the gun market.

This year, Minnesota activists and lawmakers are devoting most of their energy to pushing — or opposing — a universal background check system and a “red flag” law that would let law enforcement petition to temporarily remove firearms from those posing a threat to themselves or others.

As the national gun debate continues, research has been murky on the effectiveness of the original federal assault weapons ban, which was limited to new sales. A new Boston University study suggested that universal background checks and other measures to limit access to firearms might be more effective.

That’s not stopping advocates like Joan Peterson from urging a fresh look at doing away with the high-powered rifles, no matter how tall a task that may be.

“We have to start somewhere,” she said. “We can’t let that stop us. We can’t let that stop us.”