The Milperra Massacre, Milperra bikie shoot-out or Father's Day Massacre was a firearm battle between rival motorcycle gang members on 2 September (Father's Day in Australia) 1984, in Milperra, a south-western suburb of Sydney, New South Wales. The shootout had its roots in an intense rivalry that developed after a group of Comancheros broke away and formed the first Bandidos Motorcycle Club chapter in Australia. Seven people were killed and twenty-eight injured when the two groups clashed at Milperra. The event was a catalyst for significant changes to gun laws in New South Wales.