The new gun law to be signed by Gov. Martin O'Malley on Thursday would make Maryland among the most restrictive states in the nation for gun ownership, though other states impose even more burdens on those looking to purchase or own guns.

Maryland's new law -- one of many increasing restrictions on gun ownership in the wake of last year's mass shootings in Aurora, Colo., and Newtown, Conn. -- would ban 45 assault rifles, restrict ammunition magazines to 10 rounds, require licensing and fingerprinting for new handgun purchases, and prohibit gun ownership by the mentally ill.

Groups have long ranked Maryland among the strictest states when it comes to gun ownership -- both the Brady Campaign to Prevent Gun Violence and the Law Center to Prevent Gun Violence rank Maryland seventh among states with the strictest gun laws.

Highlights of gun laws passed since the Newtown, Conn., shooting
New York
» Ban on new sales of assault weapons, expands definition to include some shotguns and handguns
» Current owners of assault weapons must register with the state
» Seven-round limit on ammunition magazines
» Prohibits shotgun and rifle ownership by anyone under 18, unless exempted
» Prohibits handgun ownership by anyone under 21
» Prohibits ammunition sale to anyone under 18
» Bans assault weapons, limits where current owners can use theirs
» Limits ammunition magazines to 10 rounds
» Requires handgun training for concealed carry permits
» Limits ammunition magazines to 15 rounds
» Requires background checks for all gun sales, including private sales

Maryland's new law "may not necessarily make it go higher in the ranking because some of the other states that were also at the top enacted laws, like New York and Connecticut," said Lindsay Nichols, a law center attorney.

For instance, while Maryland bans copycat weapons that contain at least two features similar to those found on assault rifles -- such as folding stocks, grenade launchers or flash suppressors -- New York bans copycat weapons that contain only one of those features.

Maryland prohibits ammunition magazines that carry more than 10 rounds, but current owners are allowed to keep their magazines. New York allows only seven rounds. People can possess magazines that carry 10 rounds but cannot fill them all the way. New Yorkers also will be required to forfeit any magazine that carries more than 10 rounds.

California has microstamping technology which imprints the make, model and serial number of a gun on a cartridge as it is fired. Connecticut goes further than most states in its new law, prohibiting anyone under the age of 18 from purchasing ammunition.

Gun control opponents decry what they see as opportunism in the wake of tragedy.

"I think what ultimately this shows is what they saw was an opportunity after the Sandy Hook shooting and they used that as the basis to exploit a tragedy for their own political purposes," said Erich Pratt, spokesman for Gun Owners of America. He said the most worrisome provision was one requiring fingerprinting for new handgun purchases.

"It's really treating gun owners like sex offenders. We find that really disturbing and shameful," Pratt said.

But O'Malley's office says the law is a balanced approach that addresses not just guns but mental health and sets aside money for school safety.

"Maryland's law is a comprehensive, common-sense approach to licensing and gun safety that bans military-style and high-capacity magazines and includes meaningful improvements to mental health treatment and data-sharing -- striking a balance between protecting the safety of law enforcement and our children, and respecting the traditions of hunters and law-abiding citizens to purchase handguns for self-protection," said O'Malley spokeswoman Raquel Guillory. - Andy Brownfield