It takes seconds for a handgun or rifle to liquefy in the heat of a 2,000-degree furnace.

Afterward, the molten metal can be transformed into many things. Iron pipe. A manhole cover. An anchor.

It's a form of recycling that many local law enforcement agencies find particularly satisfying, because it ensures that those guns will never resurface in a criminal case.

"We know they're gone forever," said Melissa Young, an investigator with the Camden County Prosecutor's Office, which yesterday melted down almost 300 guns in a secret location.

The prosecutor's office seizes hundreds of firearms each year in criminal cases. Many are evidence and must remain in storage until trial or until they can be returned to their owners.

But some are found to be illegally owned or belong to people not permitted to have them back. Sometimes, no one claims a confiscated gun.

For those weapons, melting is the means of disposal that many law enforcement agencies in New Jersey and Pennsylvania prefer.

"Love it! Love it when I can melt them down!" said Michael Chitwood, superintendent of police in Upper Darby Township, which years ago sold some seized weapons to gun dealers.

"They'll never be used in a crime again, they'll never hurt anyone again," Chitwood said. "I wait until I have about 150 I can get rid of, and then we do it."

Many of the guns destroyed yesterday were taken from people who had restraining orders against them, Young said. In addition to the prosecutor's office, about a dozen Camden County police departments sent weapons to the furnace.

For security reasons, authorities refused to make public where the guns were melted, how they were transported, and even how often the process occurs.

The Camden County stockpile will be forged into 20-foot-long pipes, said Jason Laughlin, a spokesman for the Camden County Prosecutor's Office. The pipes are expected to become part of an underground water system.

Contact staff writer Allison Steele at 856-779-3838 or asteele@phillynews.com.