On June 4, a 32-year-old woman tried to get through security at San Antonio International Airport with a loaded .380 caliber Diamondback in her carry-on bag. This wasn’t a freak occurrence. Transportation Security Administration officials intercepted 18 guns on that day alone — a single-day record in what looks to be a record-setting year. The T.S.A. found 1,320 guns in 2011, 1,556 in 2012, 1,813 in 2013 — and has found roughly 900 so far in 2014.

The steady rise in guns at airport security shows that T.S.A. screeners, apart from looking out for bottles of shampoo, defend airplanes from actual weapons. It is also a vivid indication of the normalization of casual gun-ownership. Airports in states with lax gun laws tend to have the highest incidence of firearms at checkpoints.

Hartsfield-Jackson International Airport in Atlanta topped the 2013 list with 111 guns intercepted, followed by the main airports in Dallas/Fort Worth and Houston. Surprise, surprise: When legislatures send the message that guns are acceptable just about everywhere, people bring them just about everywhere.

T.S.A. officials say that offenders don’t necessarily have ill-intent; most claim they just plain forgot they were carrying weapons. And that’s part of why these statistics are so unsettling. Packing a gun in a carry-on shouldn’t be as unmemorable as packing a hair dryer, especially if that gun is loaded, as is the case with about 80 percent of all firearms intercepted by the T.S.A. Even the National Rifle Association agrees that gun owners should keep their guns unloaded until they’re ready to use them.