Transportation Security Administration screeners discovered an all-time weekly record 74 firearms in carry-on bags at US airports last week.
It beat the precious high for a single week of 68 in October last year.
The agency said 68 out of the 74 guns were loaded and 27 had a round in the chamber.
Every discovery means screening times are increased for everyone, the TSA said.
"Each time we find a dangerous item, the line is slowed down. Just because we find a prohibited item on an individual does not mean they had bad intentions. That’s for the law enforcement officer to decide," the TSA’s Bob Burns wrote on the TSA blog.
"In many cases, people simply forgot they had these items."
Although gun laws differ from state to state, Burns added that passengers can face a fine of up to $11,000.
No gun, loaded or otherwise, is allowed on a plane inside a carry-on bag according to TSA rules.
All firearms must be unloaded and placed in hard-sided checked luggage, and declared ahead of time to an airport staff.
Last year the TSA confiscated 2,653 firearms, which was a 20% increase on the previous year.
