The Carter administration is trying to get more bang for the buck out of the Navy by forgoing such "glamous capabilities" as another nuclear powered aircraft carrier, Defense Secretary Harold Brown said yesterday.

He dismissed as "nonsense" the charges that the administration is trying to reduce the Navy's military role by opting for an austere shipbuilding program.

"This administration budget and five-year (shipbuilding) program are not an attack on the Navy: sneak, kamikaze or point blank," Brown told the Chicago Council on Foreign Relations.

As evidence of the administration's "strong" support for the Navy, Brown cited the $42 billion that service is slated to get out of the fiscal 1970 defense budget, the largest slice of any service.

But "our real option" for combating the Soviet military buildup, he said, "is to outdo them in efficiency."

Deciding what kind of aircraft carrier to build next is a case in point, he said. The House and Senate Armed Services committees haver authorized building another nuclear carrier in fiscal 1979 for $2.5 billion.

"We could save $1 billion" by building the oilfired carrier rather than the nuclear one, Brown said, which could "buy us five additional modern frigates for sea-control."

"Building more nuclear carriers is not the way to compete effectively with the Soviets," he said. "If we buy them, we will actually have less defense than we could have had for the same number of dollars."

He rejected the idea that the U.S. Navy is in danger of being overtaken by the Soviet navy in the world," Brown said. "It is not going to collapse or crumble away. It is going to grow and become stronger.

"We are engaged in a marathon, not a sprint, with the U.S.S.R," continued Brown. "We need to pace ourselves accordingly. Crash programs are not what we need."

The House Armed Services Committee, in recommending a larger Navy shipbuilding program than President Carter is advocating, complained that "the president's budget of 15 ships for $4.7 billion does not begin to reverse the trend" of a shrinking fleet.

The Navy League, a private pressure group which champions U.S. Navy causes, last month passed a resolution expressing "alarm at the downward spiral in U.S. naval strength . . ."