WASHINGTON (Reuters) - The House Friday defeated its gun show bill, as Democrats and Republican moderates repudiated a bill they said had been unacceptably gutted at the behest of the National Rifle Association.

It was defeated, 147-280, by an odd fellowship of liberals and moderates who regarded the bill as too weak to be meaningful, and a small group of hard-core conservatives who shun any new gun legislation.

The top House Republican leaders -- Speaker Dennis Hastert, Majority Leader Dick Armey and Majority Whip Tom DeLay -- all voted for the bill in a strategy designed to pin the blame on Democrats for killing gun legislation.

''I am disappointed in the reaction of my Democratic colleagues who put partisanship over progress when it came to the issues of school safety and youth violence,'' Hastert said.

Propelled by public outrage after the Littleton, Colorado, school massacre by two armed, alienated and suicidal teens, the Senate last month in its juvenile justice bill included the first new gun control measures since the Republicans took control of Congress in 1994.

House Democrats tried to force an immediate vote on similar gun legislation a few days later, but House Republican leaders let several weeks elapse.

During that time, the NRA fired up its members and spent $1.5 million to make sure the House did not follow the Senate's lead, NRA chief lobbyist (and former Reagan Chief Of Staff--Rox) James Baker said.

The House and Senate must still meld their juvenile justice bills into one single measure. But with the House bill silent on guns, it now appears unlikely that all the Senate language will survive, although President Clinton and the Democrats will push for that outcome.

The central provision in the Senate bill was a requirement for background checks for all gun show transactions, whether the sales are by licensed dealers who already run checks or from other people with weapons for sale who currently are not required to do the checks.

The Senate bill gave three full business days for background checks, allowing law enforcement to access state court records if needed. The House devised a bill that cut that time frame to 72 hours, including weekends when courts are closed, and also more narrowly defined a gun show.

The House then went even further. In a vote held just after midnight Friday morning, it narrowly approved a 24-hour gun show check system sponsored by Michigan Democrat John Dingell and backed by the NRA. Law enforcement officials said passing his bill was even worse in some respects than doing nothing.

A long-time champion of gun owners, Dingell irked fellow Democrats by leading the charge on this measure alongside Republican Whip DeLay, while Clinton and other top Democrats were attacking Republicans for being pawns of the NRA.

Republicans dropped a planned amendment to raise the age for handgun purchase from 18 to 21. Currently, people have to be 21 to buy from a licensed dealer, but not from other vendors at gun shows or elsewhere.

Hastert had originally said he supported raising the age, and the White House had also pushed it. Vice President Al Gore clouded the issue and provoked many gun owners this week when he made a major speech on gun control, incorrectly saying that 18 year-olds ``could walk into any gun shop'' and buy a handgun.

The defeated House bill did include some other modest gun measures, including a requirement that child-safe trigger locks or safe storage devices be sold with all handguns and a ban on imports of high-capacity ammunition clips. Those had bipartisan support, and could possibly emerge again this year.

In a last minute move, the House also voted to relax background check requirements at pawn shops. That was a huge fight in the Senate but was almost unnoticed in the House but the amendment died when the entire bill failed.

The vote followed two days of volatile debate on a related juvenile crime bill. In that debate, social conservatives showcased their skepticism about new gun laws and their conviction that the spate of school killings can be traced to the decline of traditional values and a surge of graphic violence in teen films, music and video games.