Anxious to put a gentler foot forward, the Central Intelligence Agency estimated yesterday that the second wave of dismissals from its clandestine service would be much smaller than it expected.

Director Stansfield Turner said in a memo to all employes of the Operations Directorate that only about 50 more would have to be dropped by Oct. 1 to complete the "reduction" in force that began there last year.

The CIA director called the new projection "particularly gratifying." The agency had estimated that 225 more would have to be cut, but Turner said "the attrition rate" of employes resigning or retiring from the clandestine directorate in recent months has been much higher than expected.

But while Turner cast this as good news, one senior official at the agency attributed the abnormal attrition to low morale fostered in part by the dismissals. Since the cuts in the clandestine service were initiated, the rate has become "tremendous," running as high as 15 to 20 departures a week for the entire agency, he said. About half of that number was said to consist of employes of middle rank or higher.

Two years ago, there might have been one or two middle and upper-grade officials on the weekly attrition list, this source said. "It's the younger people who are saying there's no future in it and are leaving the agency."

The firings in the clandestine service, already battered in recent years by congressional and executive branch investigations of assassination attempts and other misdeeds, began in seemingly ham-handed fashion last fall with the dispatch of 212 curtly worded dismissal notices. A number of those who received the hand-delivered notices from William W. Wells, the CIA's deputy director of operations who was himself replaced in December, angrily complained - albeit anonymously - of the cold tone of the two-sentence notes.

CIA officials concede that the matter was poorly handled, but they also contend that the resulting headlines exaggerated the true extent of the "reduction."

"Not that many people are actually losing their jobs - very few, in fact," CIA spokesman Dennis Berend said yesterday. He said that the "reduction" will eliminate 820 jobs from the Operations Directorate, but most of these, he said, are positions made superfluous by the end of the war in Vietnam and left unfilled since.

The CIA spokesman said that 53 of the first 212 dropped from the Operations Directorate have been given jobs elsewhere in the CIA and another 50 are being considered for reassignment. Only 20 of the 212 have actually left the agency thus far, he said. Others are waiting to become eligible for retirement benefits.

The 50 additional employes to be dropped will be designated by an elaborate point system assessing their performance. Most of those who might be dropped will be notified by their supervisors within the next two weeks, Berend said. The final cuts will be made by June 1.