IF THERE is one sure-fire way to snuff out serious efforts in the neighboring states to curb the indiscriminate sales of handguns, D.C. Council Chairman David Clarke has zeroed in on it. Mr. Clarke, understandably concerned about the increase in homicides in the city, has written letters urging the Maryland and Virginia legislatures to ban sales of handguns in their states. Concluding flat out that "there is no urban beneficial purpose for a handgun," he ties this issue to the council's approval of a measure that raised the city's drinking age for beer and wine to 21. And how will this urging be received in the state capitals? For all sorts of reasons, fair and unfair, you can mark it "Return to Sender."

First, Mr. Clarke's call for a total rejection of handguns on the grounds that they are useless in a city is not what legislators from across two large states are likely to consider a diplomatic overture. Second, while the council's change in the drinking age did occur in the wake of concerns from the suburbs about under-21 drivers drinking in the District and becoming involved in fatal accidents, this wasn't the overriding reason for the council action. A federal law threatening the withholding of transportation money loomed larger at the time.

Virginia Del. Warren G. Stambaugh, a leading supporter of handgun controls, notes that a sweeping proposal such as Chairman Clarke's has a "less-than-zero chance" of being approved in Richmond. Members of Maryland's legislature also termed it unrealistic, noting that a ban on "Saturday Night Specials" -- guns used mostly for murdering and maiming -- would be difficult enough to enact.

There is no question that America's loose gun control laws have contributed to its disgraceful leadership in deaths by handguns. And the reluctance of otherwise-rational legislators to enact reasonable controls with which law-abiding gun owners and others could easily live is equally shameful. But there are many measures that could begin to bring sanity to the landscape, including uniform national waiting periods on sales of handguns and bans on Saturday Night Specials and on any plastic or other firearms that cannot be detected by airport security -- moves strongly backed by law enforcement authorities.

In the absence of effective national controls, the kind of regional approach sought by the Metropolitan Washington Council of Governments in 1981 is worth pursuing. But pushing the District's total ban on everybody else is no way to get results.