Two incumbent state delegates yesterday criticized low ratings they received in a National Rifle Association survey that gave "perfect" ratings to 12 candidates running for the House of Delegates in Northern Virginia.

Dels. Warren G. Stamburgh (D-Arlington) and Thomas Jefferson Rothrock (D-Farifax) received the association's lowest possible rating, an "F," which means that a candidate "is in favor of a ban on the private ownership of any type of firearm."

Both Stambaugh and Rothrock, say that is not true of them. They say they believe an individual has the right to own firearms. However, they favor a ban on the manufacture and sale of small, cheaply made handguns known as "Saturday night specials."

"It's a clear, deliberate distortion," Stambaugh said of the association's rating of his position. "They (the rifle association) say I don't want anybody to hear guns at all - and that's not true," said Stombaugh in seeking his third term representing Arlington.

The "F" rating "is a misrepresentation of my position on gun control," said Rothrock, who is seeking a fourth term as a delegate from southern Farifax County.

Tanya K. Metaska, an official of the association's political action committee, said the ratings of Stambaugh and Rothrock are accurate because the two men support legislation to ban some types of guns. "The right to own a firearm is circumscribed by some guns that they think should be banned," she said.

Metaska said the rifle association's survey of all the candidates running for the Virginia General Assembly has been sent to the organization's 30,000 members in Virginia.The NRA has endorsed Republican gubernatorial nominee John N. Dalton.

"On Nov. 8, 1977 YOU can be instrumental in electing pro-gun politicians to run your state government," reads the letter attached to the NRA survey. "Unless you 'use your vote to keep your guns,' the anti-gun politicians will use their vote to get your guns."

Twelve of the 40 House of Delegates candidates received an "A" rating - "solidly pro-gun, believes in the Second Amendment right." They are Republicans Vincent F. Callahan Jr. Michael D. White, John W. Adams Jr. Robert E. Harris, Lawrence D. Pratt, Paula C. Faraday, Robert E. Statz, Eileen M. Stout, and Herald G. (Skip) Beale; Democrats Floyd C. Bagley and David G. Brickley; and American Independent Party candidate C. Mason Gardner.

Rated B - "Is in favor of a waiting period prior to purchase of a firearm" are Republicans Thomas Rae Cagley, Martin H. Perper, Warren E. Barry, Halvor O. (Hal) Ekern, Geroge M. Joseph and Thomas G. Shafran; and independent John G. (Jack) Corboy.

Four candidates were given C's - "Is in favor of legislation affecting only some handguns; licensing, registration and/or prohibiting manufacture and sale." They are Democrats Dorothy S. McDiarmid, Richard L. Saslaw, and Earl E. Bell; and independent William P. Whalen Jr.

Rated D - "Is in favor of licensing and/or registration of all handguns and or firearms" were Republican Peter W. Scott, and Democrats James M. Thomson and Elise B. Heinz.

Twelve candidates either didn't respond to the questionnaire, sent in a letter, or the questionnaire was undeliverable.