Blac Youngsta Looked Relaxed, Chatted with Cops During Weapons Arrest

Blac Youngsta couldn't look more calm, cool and collected while getting arrested for gun possession -- in fact, new body cam video almost makes it seem like he was happy to kick it with the cops.

TMZ's obtained the video showing the moments after Dallas cops pulled over the MC and his crew back in October. BY clearly had a slight cough, but it didn't stop him from making small talk as the cops escorted him off to jail.

Black Youngsta was chatting them up about why the process was taking so long ... and seemed impressed with the van used to haul him away. Hell, he even asked the cop about the price of the whip!

According to the police report, a Dallas Task Force and the gang unit were conducting an operation in response to recent gun violence in Dallas surrounding multiple rap artists performing throughout the city.

Cops initially pulled over a GMC Yukon carrying Youngsta because the driver allegedly made an illegal turn. They eventually found 4 handguns ... including one between Youngsta's legs. He was ultimately arrested for unlawful carrying of a weapon.

BTW, another Memphis rapper, Lil Migo, was also arrested ... for possession of marijuana and unlawful possession of a weapon. Cops say he was in a separate SUV that was part of Youngsta's entourage.