DENVER (AP) _ One of the guns used in the Columbine High School rampage was a semi-automatic pistol favored by drug dealers and mass murderers. Federal law now bans their manufacture.

At 12.5 inches, the TEC DC-9 is short enough to hide under a trench coat.

Pro- and anti-gun forces Friday seized on news of the weapons used by the two students in Littleton as evidence that gun control laws have failed.

Although dozens of guns have been banned under federal law, those already on the market can still be sold. The DC-9 is one of them.

``This gun was made so that you can spray fire from the hip,'' said Kristen Rand of the Washington-based Violence Policy Center, which supports gun control. ``These are far more deadly than mere handguns. Their features surely increased the carnage in this tragedy.''

The arsenal Eric Harris and Dylan Klebold took to school included an assortment of homemade bombs, the DC-9, two illegal sawed-off shotguns and a short-muzzle carbine military-style rifle _ a type of gun used by two Jonesboro, Ark., students in another schoolyard massacre last year.

Federal authorities are using the serial numbers to try to track how the boys got the guns but say that will be difficult because the shotguns were originally bought in the late 1960s or early '70s. The carbine and the DC-9 have been tracked to separate dealers.

``There is no indication they belong to the parents,'' said Lawrence Bettendorf, a spokesman for the Bureau of Alcohol, Tobacco and Firearms.

It was the DC-9 that drew the ire of gun control advocates.

After some states banned Intratec Inc.'s TEC-9 in 1990, the Miami company changed the barrel so that a silencer could no longer be attached and renamed it the TEC DC-9. After the 1994 federal ban on the manufacture of certain assault weapons included both the TEC-9 and the TEC DC-9, the company changed the sling on the gun and renamed it the AB-10. Critics say the letters stand for ``after ban.''

Intratec officials didn't return calls seeking comment.

``Its a major loophole in the laws,'' said Nancy Hwa of Handgun Control Inc., a Washington group.

Even gun aficionados agree that the changes made to the renamed weapon were slight.

``What you had happen was (the government) would ban a specific weapon and the manufacturer would say, `OK, and give the weapon a different name,''' said Bob Glass, publisher of The Partisan magazine, a libertarian publication that opposes the assault weapons ban. ``The only change was that the original TEC-9 had threading on the end of the barrel which would facilitate a barrel extension, or a silencer. That's sort of the game that has been played between manufacturers and the government for the last 10 years.''

But he draws a different conclusion from gun critics. The Littleton slayings simply show that weapons bans don't work and should be abandoned, Glass said.

``These kids made pipe bombs,'' he said. ``Are you going to ban pipes? Are you going to ban trench coats?''

An Intratec advertisement said its slick pistol grip resisted fingerprints and called it ``as tough as your toughest customer.''

The guns can also carry clips of up to 32 bullets. The federal Brady Law forbids the manufacture of clips holding more than 10 bullets, but allows the sale of those made before the law.

The TEC-9 and its variations have long been associated with crime. The Center to Prevent Handgun Violence is suing Intratec on behalf of the relatives of several victims killed in a San Francisco office building by Gian Luigi Ferri in 1993. Ferri used a DC-9.

The Hi-Point 9 mm carbine rifle the gunmen used was made during the 1990s. The manufacturer's ads call it ``the hottest gun since the SKS,'' an inexpensive military-style weapon imported from China.

The two Columbine High students had stuff the baggy pockets of their cargo pants with spare magazines. They carried pipe bombs packed with nails and BBs to maximize the amount of shrapnel.