Behind the desk at Magnum Force, where rifles line the walls and pistols pack the showcases, Terry Marlow can tap into his distributors' Web sites and see listings for guns that have been banned for a decade.

The prices are there in neat columns. All that's missing is the inventory, and something tells him the blanks will be filled in very soon.

"I'm certain they've got thousands upon thousands upon thousands of them waiting to hit the market," Marlow said.

The 1994 federal assault weapons ban expires at midnight Monday and with it the prohibition against selling certain powerful semiautomatic firearms. Police chiefs, gun control organizations and a large number of Democratic politicians have lobbied for its renewal to no avail. The Republican-controlled Congress is content to see the law expire.

Yet what strikes gun dealers such as Marlow is that the rifles for sale this week will not be different in any significant way from the ones available for the past 10 years. Amid the furious political maneuvering of recent days is a situation little noticed by the public but one well known to dealers: The ban did not prevent many assault weapons from reaching the streets.

"It's a big nothing," said Gary Taepke, owner of Wolverine Shooting Sports, a gun range and firearms store in Brownstown, south of Detroit. "The ban didn't change anything. It is strictly cosmetic."

A surprising number of gun control advocates find themselves largely agreeing with that assessment, although they argue that the answer is not to end the ban but to strengthen it. The failings of the law, they contend, are the product of undesirable political compromises, not proof that their cause is wrong.

"We agree that the 1994 law is ineffective," said Kristen Rand, legislative director of the Washington-based Violence Policy Center, which estimates that U.S. companies produced more than 1 million assault-type weapons in the past decade. "Good public policy would be to institute an effective assault weapons ban."

Violence Policy Center research shows that at least 41 of 211 police officers killed from 1998 to 2001 were killed with assault weapons.

Shikha Hamilton, Detroit president of the Million Mom March, pointed to a modest decline since 1994 in the use of assault weapons to commit crimes.

"You're talking about lethal weapons that can kill a lot of people in a short amount of time," Hamilton said. "If the argument is that the ban is not perfect, I agree, but is it not better to stop part of the problem instead of opening the floodgates? The fact remains that the floodgates are set to open."

The last deluge of weapons buying coincided with the enactment of the 1994 ban, which prohibited the manufacture and sale of 19 types of semiautomatic firearms that had certain features that policymakers believed made them dangerous or popular with a dangerous crowd. These included flash suppressors, bayonet attachments, certain kinds of grips and high-capacity magazines.

But there was a time lag before the law took effect. Buyers took advantage between the law's passage and when it took effect, snapping up the soon-to-be-outlawed guns and magazines.

It was the most profitable year for Marlow, a longtime parole officer who started Magnum Force in a Monroe basement 20 years ago.

"It was like panic buying. Prices went insane. Absolutely nuts. All kinds of people, some who hadn't even owned firearms," said Marlow, 54, who named his shop for the Clint Eastwood movie. "It didn't really matter if it was an SKS or an AK-47. Everything was selling. From the standpoint of business, it was probably the best thing that could have happened."

Dealers in Michigan tell of selling Colt AR-15 rifles at a premium, only to see the buyers turn around at gun shows and sell the same weapon for twice as much. An AR-15 that sold for $750 or $800 before the ban soon sold for $1,500, then $2,000 and higher. Prices dropped as the frenzy ebbed. Hundreds of rapid-firing rifles and handguns remained legal.

Manufacturers quickly adapted to the new rules, retooling semiautomatic weapons to eliminate the flash suppressors and bayonet attachments. Firing pin diameters were changed to prevent owners from substituting fully automatic trigger mechanisms. Fully automatic assault rifles remain prohibited. Pistol grips were replaced with thumb-hole grips that served a similar function, although they looked less stylish.

The AR-15 came out in a new version, also a semiautomatic, called the Colt Sporter.

"Same gun, apart from cosmetics," said Taepke, who disdains the assault weapons ban and the politicians who back it.

The law also prevented dealers from selling guns with magazines that held more than 10 bullets, an effort to lessen the threat of mass shootings. The production of such magazines was halted, but magazines manufactured before the rules took effect could still be sold. The other day, Taepke pointed to a 33-bullet magazine for a Glock pistol that he can sell because it was manufactured before 1994.

To Taepke and other like-minded Michigan gun enthusiasts, the law seemed less about stopping crime than about passing restrictions that could be gradually expanded to take away gun ownership, which they consider a right. Wolverine salesman Justin Mundy said, "If you give a mouse a cookie, he's going to want a glass of milk."

David Coy, an Adrian, Mich., accounting professor and National Rifle Association board member, said that "as a public safety measure, it made no sense."

"As a prelude to banning more guns, the ability to ban an entire class of guns made more sense to the anti-gunners. The real issue for me personally is the notion that the ban attempted to legitimize the mythology that there are 'good guns' and 'bad guns,' " he said.

Mundy, 27, likes to shoot. He carries a Glock, an act permissible under Michigan law. He accepts the gun control argument that a weapon that fires more slowly and holds fewer bullets could reduce the chances of a mass killing. But he contends that a killer will still find a way to kill.

"It's not hard to stuff a couple of extra pistols in their waistbands," Mundy said. "People are going to do what they're going to do."

The Wolverine shop has several posters displayed prominently. One shows the Statue of Liberty adorned with a leather shoulder holster and the motto, "United We Stand." Another shows Democratic senators, including presidential nominee John F. Kerry, smiling about a gun control success and urges people to "Vote your sport." It warns, "Your firearm freedoms are at stake."

National polls suggest that strong majorities of voters and gun owners favor extending the assault weapons ban. The figures are comparable in Michigan, a state passionate about hunting. Last week the state declared open season on mourning doves for the first time in 100 years.

Kerry left the campaign trail earlier this year to cast a Senate vote for stronger restrictions and has recently stepped up his criticism of President Bush, who promised as a candidate in 2000 to extend the ban. Although Bush has reiterated that he would sign an extension if it reached his desk, he has not lobbied for it.

In a statement issued by his campaign on Friday, Kerry accused Bush of bowing to the National Rifle Association and its motivated members.

"The NRA put the squeeze on George Bush, and they're spending tens of millions of dollars to support his campaign," said Kerry, a hunter who believes the Second Amendment confers the right of ordinary Americans to bear arms. "Is George Bush going to stand with special interests or with the safety of the American people?"

On Capitol Hill, Sens. Dianne Feinstein (D-Calif.) and Charles E. Schumer (D-N.Y.) were among lawmakers who continued to push for a vote on extending the ban, but they encountered procedural difficulties and a sense of futility fueled by the virtual certainty that the House would never go along. Former president Bill Clinton has said he believes support of the weapons ban cost Democrats as many as 20 House seats.

Instead, the two senators held a news conference to urge major retailers not to sell the once-banned weapons.

The other day, a young firefighter finished a target session at the Wolverine Shooting Sports range. After putting his pistol in the trunk of his car, he talked about his enthusiasm for the end of the weapons ban. Declining to be identified, the 22-year-old said he intends to buy a fully festooned AR-15 when Colt puts them back on the market.

"I'll be there. First day. Make the collection complete," the man said with a smile. "Everybody in my family collects guns. My uncle has a big walk-in closet. I like the AR-15."

"He'll be there," affirmed his 24-year-old fiancee, who had been firing alongside him. She is a police officer in Detroit's 2nd Precinct who wishes the ban would endure. It already is easy enough to buy semiautomatic weapons, she said, but when popular guns are more available, people will buy them. In the days after a gun show, she said, police always discover more guns on the streets.

Asked about the end of the weapons ban, the couple summed up the national conundrum.

"It's bad and it's good," the firefighter said. "It's bad for police officers because more people can get them."

"But it's good," the police officer interjected ruefully, "because he wants an AR-15."

Staff writer Helen Dewar contributed to this report.

Firearms students learn the proper stance while practicing to use an Uzi at the Front Sight shooting range outside Las Vegas in 2000.Shikha Hamilton says the assault weapons ban, which is due to expire, is not perfect, but "the floodgates are set to open."