TRENTON - New Jersey moved yesterday toward becoming the second state to outlaw the powerful .50-caliber rifle that critics contend could potentially be used in terrorist attacks.

The guns, which resemble large hunting rifles, are accurate up to 11/2 miles, and opponents contend that they could be used to penetrate an airliner or ignite chemical plants, rail tank cars and refineries.

California is the only state with a similar law.

Legislation that would make New Jersey follow suit was released yesterday by an Assembly committee and can now be considered by the full Assembly.

The proposed ban is getting renewed attention after federal investigators announced this week that they had foiled an alleged terrorist plot by six men who were planning to attack Fort Dix.

"As unnerving as the Fort Dix terrorism plot was, it could have been all the more worse if the weapons of choice for alleged assailants had been .50-caliber assault guns instead of AK-47s," said Assemblyman Reed Gusciora (D., Mercer).

The six men arrested Monday night allegedly tried to buy AK-47 assault weapons, M-16s and other weapons from a government informant.

The bill is opposed by gun-rights advocates, who contend that it would do nothing to stem gun violence.

"Gun bans will not stop a criminal intent on doing harm because the criminal mind will always find another tool," said Scott L. Bach, president of the Association of New Jersey Rifle & Pistol Clubs. "This feel-good legislation disarms only responsible citizens and does nothing to prevent crime."

The bill would include .50-caliber weapons in the same law that bans explosive devices. Violators would face up to five years in prison and a fine up to $15,000.

The proposal would exempt antique guns and traditional rifles that fire a single shot. It would also allow people who own a .50-caliber weapon before the law takes effect to keep their weapon.