In the booming business of fireworks, you only get one shot at success each year.

Washington's pyrotechnical firms seem confident that this year's July 4th firework sales will be strong -- with one caveat.

"We expect sales to be very good this year, yet there is no way of telling till after the holiday weekend and anyone that tells you different is full of baloney," said Jimmy Piccolo, manager of Souveir City, which is a major year-round retail outlet for fireworks in the District.

Piccol, who has been in the business for 20 years, said sales for this one week are almost equivalent to those for the other 51. He keeps nearly 10 times the normal amount of inventory on hand for the once-a-year sales bonanza.

"The peak season for fireworks is a short period, say 10 to 14 days before the 4th" of July, said Milt Dropo; owner of the Washington Fireworks Co. He owns one of the major fireworks import and distribution companies in the area and a similar operation in Alabama.

Dropo has made a number of trade trips to the People's Republic of China, keeping abreast of an ever-increasing flow of fireworks imported from the mainland. Over the past decade the amount of fireworks imported from China has nearly quadrupled, rising from $7 million in 1970 to $26 million in 1979, according to figures compiled by the U.S. International Trade Commission.

Dropo said that most of the fireworks he distributes in the Washington metropolitan area are domestically produced because of local regulations. Washington, like many major urban areas, has stricter laws concerning the use of fireworks. Therefore, the marketing trend is different than elsewhere in the country, where imported Chinese fireworks account for nearly 85 percent of the total U.S. market.