From the Boston Herald:

Gun rights groups are trying to block the state attorney general from enforcing a state regulation barring the commercial sale of certain semiautomatic pistols.

Bellevue, Wash.-based Second Amendment Foundation and Boston’s Commonwealth Second Amendment Inc. say the regulation requiring a “load indicator” on a semiautomatic handgun is “unconstitutionally vague and ambiguous.”

It affects the sales of third- and fourth-generation Glocks to civilians, said Alan Gottlieb, founder of the Second Amendment Foundation, which filed a lawsuit yesterday in U.S. District Court in Boston.

On several pistols I’ve owned over the years, the ‘load indicator’ was pretty oblique. The only way to be absolutely sure is to check the chamber directly.