Capt. W.K. Bell of the Toronto Scottish Regiment came to Washington recently leading a military musical pageant of 350 Canadian Armed Forces bandsmen - Royal Canadian Dragoons in blazing red jackets, Queens York Rangers with brass glittering, and, playing bagpipes, 48th Highlanders, Black Watch of Canada and Princess Pat's, in varied tartan kilts.

Except for Capt. Bell, they all flew to Washington in two shoeboxes.

He came for the National Capital Military Collectors' annual show, and although his "massed bands" didn't win the Grand Master prize he had a good time. He dressed up in his uniform and played marches on a tape recorder hidden under a display table.

There are 310 National Capital Military Collectors, and it would be impossible to count how many Americans are aficionados of militaria. Anyone who owns an old army helmet or a handful of ancient tin soldiers could qualify.

What brings military miniature collectors together and turns them on is history. Starting with a figure of lead, pewter, tin or plastic, they take three or four hours just to paint it to be historically accurate. They consult books, old paintings, old photographs and one another. They try not to get discouraged when pictures show just the front of a uniform.

Avid collectors don't stop at painting William the Conqueror. They learn the details of the Battle of Hastings and recreate it in a diorama. And then they might refight it in the basement.

Collectors love color and pageantry. Napoleonic France is the favorite, followed by Victorian England. One collector thinks Nazi Germany is high in popularity - third - because "Their uniforms looked like they just stepped out of the early 1900s."

Some people think collectors of toy soldiers are oddballs. And they're not called toy soldiers, by the way; they're military miniatures.

You'd think kids would be aching to play with their parents' soldiers, but collectors don't count on starting a family tradition. None of Capt. Bell's three sons now collects model soldiers. One collects model air planes, but, Bell says, "They're modern planes. Not the old Spitfires or Hurricanes. Now that's what a plane should look like."

Having emigrated from Scotland to Canada in 1955, Bell works as a budget analyst for the Canadian Ministry of Housing. He discovered miniatures 15 years ago when he commandeered his first son's small collection. "He wanted a marching band. So we went and looked at some soldiers. I saw if I switched a head here and there and put a wee splash of white on the cuffs instead of the gray that was already there, he'd have his band. And I was hooked."

That same year Bell met fellow collector Ernest J. OWen, an insurance claims representative in Virginia and founder of the National Capital Military Collectors. Owen had gone to Toronto to visit friends who quite frankly thought his avocation strange but invited someone else to dinner who also liked miniature soldiers. That was Bell, and they've been friends ever since.

Owen's interest in militaria was inevitable, he says, because he was "born and raised in the Army." In those days, the late '30s and early '40s, a popular notion among little boys was that lead soldiers were made from "pieces of shrapnel from German bombs." (Germany wasn't making too many lead soldiers, actually. A clause in the Treaty of Versailles prohibited Germans' making metal toys that could be considered "emblems of Prussian militarism." They evolved a sort of papier-mache figure instead.)

Owen remembers that before World War II he could buy eight lead soldiers from W. Britain's Ltd., for 70 cents. To show how things have changed, at a Sotheby Parke Bernet toy auction in New York in June, a "lot" of 37 lead soldiers like those went for $300.

David Redden, an assistant vice president of SPB, says they've gotten so many calls from collectors wanting to sell that they're considering a special sale solely of toy soldiers, "something that just doesn't happen in America."

SBP won't handle soldiers in anything less than perfect condition - "Paint flakes off easily from lead," Redden says, "and most people have been playing with them."

Bell originally spent between $600 and $700 on the 350 bandsmen he brought to Washington out of his collection of 1,800. A dealer at the show said Bell's collection is now worth "thousands," as it contains numerous Britain's lead figures, no longer manufactured.

Yet military miniatures of some kind are within reach of a child's allowance. Pewter or metal alloy figures of 54 mm. can be made from kits costing $4.50 and up. Or one can buy a plastic figure, ready made, for $1.50 or $2 and, with an electric hot knife and an emery board, turn Napoleon into Lady Godiva.