A 74-year-old jeweler who had operated the same shop in downtown Washington for more than four decades was shot to death yesterday by one of two armed bandits who unaccountably slipped through his security system.

Ernest Burk, owner of Ernest Burk, Inc., of 614 13th St. NW, was pronounced dead at 11:10 a.m. at George Washington University Hospital of a single bullet wound in the stomach. His assailants escaped on foot.

During his years at the store, Burk had been held up several times, although he had not been injured in the earlier robberies.

Burk's fear of further violence led him to install a security system that required the pressing of a device on the floor to open the store's front door, investigators said.

This was done at 10:30 yesterday morning, police said, to admit the two young bandits. What motivated Burk to release the door latch still was unknown last night.

Seconds after they had entered, both bandits produced pistols and one shouted, "This is a holdup." Burk immediately began struggling with the pair and fell when the single shot was fired.

Police would not say whether anything was taken or how many sales clerks or cusltomers were in the store at the time. They did disclose that Burk's wife of 28 years, Sylvia, was present, although it was not clear whether she witnessed the shooting.

Burk immigrated to this country from his native Germany in the 1930s, settled in Washington and soon opened the business to which he brought - in the words of his wife - the "perfectionism" of the old world craftsman.

"He was more or less a workhorse," Mrs. Burk todl a reporter last night. She added that Burk's striving for perfection in his work, and in his dealing with long-time customers, led him to conclude that no one can ever learn "everything about anything."

"But," his wife added, "he often said, 'when its time for you to die, then you may know something'" about the task to which one has devoted his life.

This, his customers and one of his neighbors agreed, was Ernest Burk's style. Dr. Alvin C. Wyman, a radiologist and a neighbor of the Burk home on 28th Street NW, told a reporter that "it is totally, completely uncharacteristic of him to have put up a struggle."

"He once said to me. 'I don't care if they appear unarmed. I would not put up an argument because, after all, it's only money,'" Wyman recalled.

Dorothy Hurley, a customer of Burk's since 1943 who had planned to drop off her watch for repair yesterday, said that Burk had been troubled deeply by violence in the 13th Street area.

"For the last five years," she said, "he had been scared to death."

Hurley's account, along with other similar ones, police said, left them with the unanswered question of why Burk had opened his door to the men who were to kill him.