A Tyngsboro resident is about four times as likely to own a gun as someone in Lowell, and anyone in Wilmington, Groton, Billerica and Tewksbury is also more than three times as likely.

Even among similar cities in Massachusetts, Lowell has a lower gun ownership rate than most. It is far behind Chicopee, Haverhill or Pittsfield, for instance. But Massachusetts cities generally trail smaller communities, in some cases by multitudes, when it comes to gun ownership, according to state data.

A few reasons could account for the lower rates. Lowell Police Superintendent Kenneth Lavallee has estimated that 90 percent or more of the licenses are for hunting or target practice, and said Lowell residents generally aren't as likely to be target or shooting hunters. The city also has a higher standard than most for approving permits, he said.

Two other Massachusetts cities illustrate how police departments can keep gun ownership rates down.

The city of Chelsea, with more than 35,000 residents tightly fit in only 2.5 square miles, has a policy similar to a probationary period for applicants. They first allow permits only for sport use, and if a year passes without incident, they can have an unrestricted license, said Det. Myles Cohen, who reviews permits for the police department.

The city had only 428 Class A licenses, by far the most common license category, last year, less than even the town of Littleton. It has traditionally been tight on allowing guns, Capt. Keith Houghton said.

"The two previous chiefs basically never gave them out. They'd be in court fighting it," he said. "We're still restrictive."

Quincy, a city of 92,000, also has a low gun ownership rate per-capita but it also has an exceptionally high increase, 53 percent, during the past five years, according to data from the state Firearms Records Bureau. It has more than 2,300 owners of Class A licenses, which allow for possessing and carrying handguns, shotguns, and feeding devices, including carrying concealed guns.

Quincy's increase can be attributed to the difference between a former police chief and the current chief, Paul Keenan, said Capt. John Dougan, the department spokesman.

Keenan, who took over in 2008, is less stringent and goes by what state laws says on gun permits, Dougan said. But the department still restricts applicants 25 or younger, allowing them licenses only for hunting and targeting.

The increase hasn't led to more gun-related crimes, according to the police department. In the past five years, Dougan said, the city has had only three homicides and none were gun-related.

Lowell, despite an increase of 36 percent in the number of Class A permits, has not had a gun homicide in two years, according to the police department. Lavallee said he has a strict standard for approving permits. He might issue only a target and hunting license if an applicant does not meet stricter guidelines, he said, such as if they are a victim of a crime looking for better self-defense, or if they need a gun for work.

Gun ownership across the state, including greater Lowell communities, has risen dramatically in the past five years, according to the number of residents in each community with a Class A license.

Ayer, Groton and Pepperell had increases of 40 percent or more. Billerica, Chelmsford, Dracut, Westford and others experienced jumps of at least 30 percent.

A Class A license is the broadest category, but the state also gives Class B licenses, which allow for non-large-capacity handguns, rifles and shotguns. In Massachusetts, anyone looking to obtain a gun license must first pass a firearms safety course. The minimum age is 21 for a Class A or Class B license.

For a Firearms Identification Card, which allows the purchase, possession and carrying of nonlarge capacity rifles, shotguns and ammunition only, a person may be 18 years old. Someone as young as 15 can qualify for an FID card with parental consent.

Gateway cities -- Lowell and 23 others that share economic similarities and manufacturing histories -- experienced similar but often lower increases in the past five years.

On the higher end, increases of at least one-third have been experienced in Lowell, Haverhill, Barnstable (which includes Hyannis), Malden and Salem. Quincy has the largest increase at 53 percent. Some cities had slighter increases, including Chicopee and Everett, which were each 9 percent, and Revere and Worcester, each 11 percent.

Generally, the cities farthest away from Boston, including Barnstable, Pittsfield, Taunton and Westfield, had far higher rates than those closer to the capital.

Cities, despite those increases, still generally trailed smaller communities by significant margins in per-capita gun ownership. Gun-store owners and police chiefs, who ultimately hold the authority of whether to grant a license, said earlier this month that a big share of gun ownership is either for sport, such as hunting, or for self-defense.

Follow Grant Welker at Twitter.com/SunGrantWelker.