When the robber walked into the Caprice Villa Lounge carrying an Uzi-like weapon, the bartender's brother reached down as if he were going for a gun.

"We just thought someone was playing at first," said Marcia Williamson, the bartender and manager.

Her brother did not have a weapon - and the bandit was not joking.

"He said, 'No, old head, don't do that,' " Williamson said yesterday. "That's when my brother knew he wasn't playing."

The Caprice, a West Philadelphia mainstay, was the second of six businesses the bandit and his sometimes accomplice have hit since Tuesday night, when they robbed the establishment.

The two apparently youthful criminals remain at large, and detectives are worried about such heavy firepower in inexperienced hands.

The robbers have struck three West Philadelphia bars in their spree, in each case walking into a culture clash with patrons and owners at least a generation older than them.

Two of the bars - the Caprice, at 5000 Market St., and Neet's Bar & Lounge, up the street at 5127 - have been owned by the same families for nearly three decades.

Those two bars, along with the third, Smitty's Millcreek at 601 N. 52d St., have long-standing older clienteles and almost no experience with being robbed.

"I've been coming to this bar since the late '70s," Williamson said. "Never before have I had anything pointed at my face."

Up the street at Neet's, under the Market-Frankford El, the owner's nephew, Wafare Ali, described the family business as "an old-timer's bar."

"You're not going to get any money out of here," he said. "You take $2 off one person, $3 off one person. Come on."

He said his "Aunt Neet," who was not at the bar yesterday afternoon, is in her early 70s.

"And he put the gun to her head," he lamented.

While the robber's weapon was described as an Uzi, experts who viewed surveillance from one of the robberies have determined that the gun is a Mac-10, a similar firearm, police said.

There is no way to tell from the video whether the machine pistol is semiautomatic or has been converted illegally to fully automatic. In full auto, its rate of fire is more than 1,000 rounds per minute. Its magazine can carry up to 30 rounds, police said.

A second bandit, who accompanied the robber with the Mac-10 in at least three of the jobs, carries a 9mm pistol, police said.

The criminals haveworn masks in all the robberies and escaped in each case on black BMX bikes.

After the robbery at Smitty's Millcreek on Wednesday, patron Anthony Wilson chased the bandit as he pedaled away.

"I almost caught his ass," he said.

As the robber was leaving the bar, he said, "Thank you, have a good night," Wilson said. "Just real arrogant."

Police have warned residents not to try to apprehend the bandits, but Wilson said he is a Christian and not afraid.

"If I get killed by the instrument of somebody's hand, that's just the tool the Lord used to call me home," he said.

Late yesterday afternoon, police officers flooded the intersection of 52d and Arch Streets, passing out fliers to pedestrians and motorists about the robberies and other crimes in the district.

"It's an opportunity for us to meet and greet people," said Lt. John Walker of Southwest Detectives. "We might get a tip that leads to our suspects."

Police are concerned because in each robbery, the main bandit has pointed the Mac-10 and threatened to shoot.

In the Caprice, the robber kept saying, "There's got to be more money than that. Where's the safe?" Williamson said.

When she told him there was no safe, the robber told them, "Y'all gonna make me kill you," she said.

Ali said that in the 37 years his family has owned the bar, "it might have been stuck up twice."

"We know everybody," he said. "We raised all of them."

Anyone with information about the bandits is being asked to call the police tip line at 215-686-TIPS or Southwest Detectives at 215-686-3183.