Martin S. Feldstein, chairman of the Council of Economic Advisers, said yesterday that, if the economic recovery began in January, "I would not be at all surprised to see 5 percent real GNP growth in 1983."

A few private economists, including George Perry of the Brookings Institution, now expect the economy to expand at least that fast during the year.

Perry this week predicted that the gross national product would increase 5.7 percent, after adjustment for inflation, between the fourth quarter of 1982 and the fourth quarter of this year. That contrasts with the administration's official forecast of a 3.1 percent rise and with a variety of other private forecasts clustered generally between 3.5 percent and 4 percent.

Feldstein told the House Appropriations Committee that if the recovery did not get going until April or May, then growth might be as low as 2 percent this year. "At the present time, it is best to avoid the optimistic or pessimistic extremes and to use a forecast that represents a balance of probabilities.

"I believe that our forecast of 3.1 percent growth in 1983 is a cautious and prudent estimate that reduces the risks of unpleasant surprises without being unduly pessimistic," Feldstein said.

Meanwhile, the Commerce Department reported that new orders for manufactured goods rose $7.3 billion or 4.8 percent to $157.6 billion in December largely on the strength of a surge in defense orders.

On the basis of that and numerous other signs that production declines are probably at the low point of this business cycle, some economists believe the recession is over.

For the longer term, between 1984 and 1988, Feldstein said the administration is forecasting that the economy will grow at 4 percent a year. However, he added, "We recognized that there will be some years in which real growth exceeds 4 percent and others in which it is less than 4 percent. But we don't pretend to have the ability to forecast these year-to-year oscillations."

Perry bases his forecast of strong growth this year, in part, on an assumption that the Federal Reserve acts to keep short-term interest rates close to current levels throughout the year. "We are always hostage to the Fed," he cautioned, "and a real move back up in rates could abort the recovery."

Nevertheless, Perry is convinced that the Fed is "ignoring" growth of the money supply for now and focusing instead on interest rates. With rates down, and in his opinion little likelihood they will go back up soon, he expects the economy to take off.

"We are in a situation with a good deal of pent up demand that has been constrained by interest rates. With them down, there is not anything really surprising" in my forecast, he said.

Other forecasters show various sectors of the economy moving in much the same directions as does Perry, but generally they do not expect such large increases in consumer spending or inventory accumulation as he does.

Nor are they quite as sanguine as Perry about the Federal Reserve's intentions. Long-term interest rates, including fixed-rate mortgages, have been rising recently and there was an indication yesterday that the Fed may not try to bring them down again by lowering short-term rates.

Federal Reserve Gov. Nancy Teeters, addressing a Washington group, said she would like to cut the Fed's discount rate--the rate the central bank charges on loans to financial institutions--but that she needs "a few more votes" on the board before that can happen. CAPTION: Picture, no caption; Chart, FACTORY ORDERS, New orders for goods climbed 4.8 percent in December to $157.6 billion for the strongest monthly rise in 2 1/2 years, but the $7.3 billion increase was due entirely to a gain in defense orders, and the year's total was 6.4 percent below 1981's level. By Kathy Jungjohann for The Washington Post