WHITE HILLS, Ariz. — Antonio Nárdiz, a Spanish tourist from Bilbao, said he had chosen a family vacation to America for one specific reason: to fulfill his sons’ dreams of firing real machine guns. In Spain, he noted, 10-year-old Jon and 12-year-old Toni, like all other civilians, are forbidden to use automatic weapons.

Mr. Nárdiz, 47, had heard that a family trip to an American gun range turned tragic last year when a 9-year-old girl lost control of an Uzi submachine gun, killing her instructor. So when Mr. Nárdiz selected that same range for his family’s adventure — a place called Last Stop, just an hour’s drive from Las Vegas — he called ahead to ask about security. Someone told him, “It’s practically impossible for an accident to occur,” he said.

In the year since a New Jersey girl visited Last Stop and accidentally killed Charles Vacca, a 39-year-old father of four, little has changed in the nation’s tourist-oriented machine gun ranges. Last Stop’s range, which receives 100 to 200 visitors a week, is one of about a dozen places in the Las Vegas area that offer machine gun adventures.