By Richard Allen Greene
BBC News Online in Colorado
Americans have strong feelings about the expiration of a national ban on assault weapons like AK-47s and Uzis - on both sides of the issue.
The gun lobby says people have a constitutional right to firearms
Darrin Duber-Smith, a marketing consultant and professor, argued passionately that the ban was unimportant.
"I am not concerned. Automatic weapons have been illegal for years," said Mr Duber-Smith.
"You can kill someone with a handgun, a knife, you can strangle him with your hands. What's the big deal with assault weapons - you get more bullets? I don't get it. Why are we worrying about this?" he asked rhetorically.
"Violent crime is the lowest it has been since we began measuring in 1973," he asserted.
But Asif Rahman, a software salesman from Washington, DC, called the expiration of the ban "a horrible thing".
"Things are bad enough without assault weapons," he said, adding that it was especially striking to be in Colorado on the day the ban expired.
Colorado was the scene of the massacre at Columbine High School in 1999, where 12 students were killed in a shooting spree by fellow pupils Eric Harris and Dylan Klebold.
They carried out the killings with shotguns and
semi-automatics purchased by a friend at a gun show. The guns were not covered by the assault weapons ban - which was in place at that time.
It was passed in 1994. Under a deal between supporters and opponents of the measure, it expired automatically after 10 years unless Congress voted to renew it.
The Republicans who control Congress now did not schedule time for such a vote. President George W Bush did not press them to do so, although he says he supports the ban.
John Kerry, Mr Bush's opponent in the November presidential election, criticised the president over the issue.
"Tomorrow for the first time in 10 years when a killer walks into a gun shop, when a terrorist goes to a gun show somewhere in America, when they want to purchase an AK-47 or some other military assault weapon, they're going to hear one word: 'Sure,'" Reuters quoted him as saying.
The National Rifle Association, a lobbying group that opposed the ban, hailed its demise.
"As was the case for decades prior to and during the life of the ban, criminals still will not legally be able to possess these firearms," the group said in a statement.
"Law-abiding citizens, however, will once again be free to purchase semi-automatic firearms, regardless of their cosmetic features, for target shooting, shooting competitions, hunting, collecting, and most importantly, self-defence."
Max Smith, a former estate agent, said he did not see the need for individuals to carry military-style weapons, but was not concerned about the expiration of the ban.
"I don't think it's that important. If terrorists or criminals want them, they'll get them," he said.
Mr Smith - who owns a handgun for protection, he said - does think Americans should be allowed to have guns.
"I'm not a big gun guy, but if private citizens want guns, they should be able to have them. It's constitutionally protected."
But legal assistant Deb Dore, who has been robbed four times in the past year, called the end of the ban "frightening".
"The streets aren't safe, with prostitutes and crack cocaine, and now, to put assault weapons into these people's hands? I'm tired of these crooks. They're costing us too much."