The Government Accountability Office report indicated people with clear links to terrorist groups had regularly taken advantage of gaps in gun legislation.
The study concludes the FBI "could better manage" its gun-buying records in matching them against lists of suspected terrorists, as at least 44 times from February 2004 to June, people whom the FBI regards as known or suspected members of terrorist groups sought permission to buy or carry a gun.
Sen. Frank Lautenberg, D-N.J., who requested the study, said he plans to introduce legislation to address the problem in part by requiring federal officials to keep records of gun purchases by terror suspects for a minimum of 10 years.
Such records must now be destroyed within 24 hours as a result of a change ordered by Congress last year.
"Destroying these records in 24 hours is senseless and will only help terrorists cover their tracks," Lautenberg said. "It's an absurd policy."