Gun rights groups say the ban applied to guns that were no more dangerous than legal guns, and only looked more fearsome. Gun control advocates say the weapons that are now available can shoot more bullets faster, and could kill cops and innocents.
The 1994 ban, signed by President Clinton, outlawed 19 types of military-style assault weapons. A clause directed that the ban expire unless Congress specifically reauthorized it, which it did not. That means firearms like AK-47s, Uzis and TEC-9s can now be legally bought.
Claiming the ban precipitated a 66 percent drop in the use of these military-style weapons in crimes, Democratic lawmakers tried to inspire fury over its expiration, reports CBS Early Show National Correspondent Thalia Assuras.
In newspaper and broadcast ads, the ban's supporters claimed its expiration would make it easier for terrorists to obtain dangerous weapons.
But National Rifle Association President Wayne La Pierre told the CBS News Early Show that he "doesn't buy" polls showing 68 percent of Americans believe the weapons ban should stand.
The anti-gun lobby, he said, has fooled the public into thinking the ban applies to machine guns used in warfare.
In fact, LaPierre said, "The truth to the American public tomorrow morning when this law expires, there is not one gun available that makes bigger holes and shoots more rapid."
Studies done by pro- and antigun groups as well as the Justice Department show conflicting results on whether the ban helped reduce crime. Loopholes allowed manufacturers to keep many weapons on the market simply by changing their names or altering some of their features or accessories.
U.S. Rep. Butch Otter, R-Idaho, trumpeted the end of the federal law.
"President Clinton's so-called 'assault weapons' ban was nothing more than a sop to antigun liberals," Otter said Friday in a written statement. "It provided only the illusion of reducing gun violence, but it did real damage to our liberties."
The ban's proponents are pleading in a letter to large retailers, including Wal-Mart and Kmart, not to stock assault weapons. Both companies say they will not carry the weapons.
Deborah Curtis, a Virginia gun store manager, says they are not stocking up either.
"There's not a lot of people coming in and saying, 'Well, gee, we can't wait until this is over,'" Curtis said.
At the Boise Gun Co., gunsmith Justin Davis last week grabbed up a black plastic rifle resembling the U.S. military's standard issue M-16 from a row of more than a dozen similar weapons stacked against a wall.
The civilian version of the gun, a Colt AR-15 manufactured before 1994, could be sold last week just as easily as it can be sold this week. "It shoots exactly the same ammo at exactly the same rate of fire," said Davis.
But advocates for the ban point to some particularly vicious shootings in which military-style weapons were used — including the 10 killings in the sniper shooting spree that terrorized residents in Maryland, Virginia and Washington, D.C., in 2002.
National police organizations such as the International Association of Chiefs of Police, the International Brotherhood of Police Officers and the Fraternal Order of Police all support the renewal of the ban.
Sarah Brady, a leading gun control advocate since her husband, former White House press secretary James Brady, was shot in the 1981 assassination attempt on President Reagan, told the Early Show the ban would allow more dangerous guns on the streets.
"There is nothing cosmetic about this law," she said, claiming that it will allow Americans to own guns with large ammunition clips and the ability to fire very rapidly.
Under the 1994 ban, the maximum capacity of a magazine was set at 10 rounds. Now, some gun manufacturers are planning to give away high-capacity magazines as bonuses for buying their weapons. Sales of formerly banned gun accessories, such as flash suppressors and folding stocks, are also expected to take off.
Critics contend Mr. Bush could have led the battle to save the ban, but is keeping silent in order to reap votes from the NRA.
"He tried to say on one hand that he was for the ban," Brady said. "But he has done absolutely nothing, exerted no leadership to be sure that the House and the Senate would bring it up and pass it."
"It did pass in the Senate in March," Brady added. "The House has said they will not bring it up if the president didn't ask for."
Democratic presidential nominee John Kerry is also criticizing Mr. Bush for letting the decade-long ban expire.
"George Bush made a choice today," the president's Democratic challenger said in remarks prepared for a Washington audience Monday. "He chose his powerful friends in the gun lobby over the police officers and the families he promised to protect."
Appearing with Brady, Kerry said renewing the assault weapons ban would not interfere with the Second Amendment rights of gun owners.
"Let me be very clear. I support the Second Amendment. I've been a hunter all my life," Kerry said. "But I don't think we need to make the job of terrorists any easier."
Bush-Cheney campaign spokesman Steve Schmidt said, "Senator Kerry has spent his entire 20-year career in the U.S. Senate fighting against Second Amendment rights."
Many states — including California, Massachusetts, New York and Hawaii — have passed their own laws curbing the use of assault weapons. Some of those are more stringent than the federal ban.
The expiration of the assault weapons ban does not mean the end of federal background checks. The 1993 Brady Handgun Violence Prevention Act is separate legislation from the assault weapons ban, said Daniel Wells, chief of the FBI unit charged with overseeing the background checks system.