The Shotgun News may be the straightest-shooting periodical in the country.

Where else can you go if you're in the market for an M3 U.S. Army halftrack in working condition with all armor? ($6,500 from Ostrander, Ohio.)

Or a precision blowgun? (28 inches long with 12 darts, $13.98.) Or an SSK Handcannon? (Uncommon Guns for Uncommon Men.)

Or an "I

My Uzi" bumper sticker?

Never mind the outlets for AK47 assault rifles, belt-fed Browning machine guns, Sten guns and Bren guns and tank periscopes and deer meat jerky. With 220-odd newsprint pages of such explosive classified ads, untroubled by editorial content, the Shotgun News is, three times a month, for $15 a year, a piece of genuine Americana.

While yuppie-targeted magazines bloom and die by the annual basketful in the nation's urban markets, Shotgun News blasts along from its base in decidedly nonyup Hastings, Neb., grossing some $12 million annually from its 189,000 subscribers countrywide in this, its 41st year.

Robert M. Snell, 49, its low-key publisher, runs it handily with 28 employes in Hastings and another 30 in Minneapolis, where the News has its own 30,000-square-foot printing plant. It leaves him plenty of time for his bowling alley, travel agency, 30 racehorses and thoroughbred breeding farm.

"My father started it," Snell said by phone from Hastings the other day. "He was a mailman, and during the war was stationed up in the Aleutian Islands. They used to lie around up there thinking of how to get something going when they got back."

When the elder Snell returned to his home in Columbus, Neb., in 1946, his son says, "he bought a few lists of names, got more addresses from some outdoor magazines and sent out the first issue" -- four pages of ads cranked out on a mimeograph in his basement.

"It was self-supporting from the start," Snell says.

It also was and remains, he adds, "aimed at the collector," and the bulk of the ads feature things like ivory pistol grips for .45 Colt revolvers, or replacement barrels for Walther PPK automatics like James Bond's. But the legend on the masthead calls Shotgun News "The Trading Post for anything that shoots," which also makes it something of a bulletin board for the darker side of the American psyche.

"Going South?" asks a front-page commando school ad in a recent issue. "Learn from the Pros! Affordable Prices. $1 for brochure."

"GET EVEN -- The Complete Book of Dirty Tricks," whispers another. "This ultimate work in do-it-yourself justice makes other harassment books look like a Sunday school picnic ... Here is a manual written by a master of revenge whose wisdom will put you on top of any situation where you used to feel helpless ... Getting back at a landlord, politician, salesman, utility, restaurant or supermarket is a cinch with over 130 creatively nasty techniques ... $16.95."

"TRANSFERABLE MACHINE GUNS?

YES!

" trumpets still another. "... The new machine gun prohibition has not even slowed SWD DOWN! We have in stock newly manufactured AK47 7.62 Norinco machine guns. These were made in the Chinese 66 Factory ... Full auto quality weapons..."

Others among the Rugers and Lugers advertise cryptically for "The Anarchist Cookbook" (Hollywood, Calif.), "Nazi Gun Parts" (Dunedin, Fla.), and the privately published memoir of one Col. Charles Askins who "raises Hell around the world" and "snuffs out Arabs, Germans and Italians in WW II ..."

Publisher Snell takes a generally laissez faire, free-speech attitude toward ads of this kind, acknowledging that some people won't like them, "just like some people won't like The Washington Post." But he says he regularly rejects ads promoting anything clearly illegal ("We won't carry ads for silencers, for example") and won't run pornographic ads. "Somebody," he sighs, "always wants to put a naked woman on a gun to get attention."

Here in supremely political Washington, where the world of the firearm remains, to many, a one-dimensional, pathological and fearsome realm, the pistol-packing pages of the Shotgun News probably look like a blueprint for guerrilla war in the streets.

But they may be more valuable for the surplus store perspective they provide of that world, in all its variety, wistfulness, craziness and clamor. Shotgun News subscribers, its publisher says, are distributed fairly evenly across the country by population, in every state in the union. The District of Columbia, for example, has 156.

And if you can find a source in Shotgun News for a German World War II bazooka manual, you can also find one for western short duster coats "duplicate of the one worn by John Wayne in 'True Grit,' " together with "genuine steer skulls and chuck wagon gongs."

If you can find "Genuine Authentic Gurkha Knives ... relied on ... from Gallipoli to the Falkland Islands," you can also find an original British Guards Uniform Tunic, complete with bearskin busby.

Who, do you suppose, dresses up in that?