"This has never happened before. We've made history, we got two pieces done. . . . We have started the engine moving," Rep. Thaddeus Kirkland (D., Delaware), chairman of the 17-member caucus, said Friday.
Kirkland said his caucus would not hold up the budget vote, which is stalled amid tense negotiations.
"If the vote comes tomorrow, we're on board because we have provided people with hope," he said.
But Kirkland said the caucus would hold House leaders to their commitment to pursue talks on stronger gun-control legislation this summer.
The measures were sponsored by lawmakers whose lives have been touched by gun violence.
Rep. John Myers (D., Phila.), whose 26-year-old son was kidnapped last year at gunpoint and is still missing, sponsored the firearms-tracing amendment, which passed by 196-2.
"People ask, 'How do young people get weapons?' " he said. " 'Where do these young people get these weapons from?' "
Kirkland, who has left a bullet hole in a side of his car to show his constituents that he has not forgotten them, sponsored an amendment, which passed 197-1, to add rifles and other long guns to the definition of firearm. He said that would increase the penalty for crimes committed with a long gun.
Kirkland said the Myers amendment would compel law enforcement to trace the weapons, which he said was clearly not always being done.
The law requires local police to use the National Tracing Center of the Federal Bureau of Alcohol, Tobacco, Firearms and Explosives.
The measure also would require the state police to create a registry of recovered weapons from people under age 21.
Before the vote on each amendment, Rep. Edward Staback (D., Lackawanna) stood to assure lawmakers that the NRA had signed off on the bills.
NRA lobbyist John Hohenwarter said the legislation would "make a difference in crime."
"In Philadelphia, we've been asking for the enforcement of laws for years," he said.
Philadelphia Police Commissioner Sylvester M. Johnson was not available for comment Friday. His spokesman said department officials could not comment until they had studied the bills.
Other law-enforcement officials, speaking privately, said the measures would not stem the violence in the city.
But Phil Goldsmith, president of CeasefirePA, called their passage an important first step toward combatting gun violence.
"I believe the legislature is hearing footsteps on this because people are dying," he said.
Rep. Jewell Williams (D., Phila.) said it was the history-making beginning of a dialogue about gun violence and about crime.
Kirkland called it the beginning of a long process.
"This is not a cure-all for crime," he said. "We want to put through much stronger legislation."
Contact staff writer Amy Worden at 717-783-2584 or firstname.lastname@example.org.
Staff writer Joseph A. Gambardello contributed to this article.