What does "carrying a gun" mean in Yangzhou dialect?

In Yangzhou dialect, "old back gun" means stabbing a knife from behind. It belongs to the southwest mandarin-Sichuan, Guizhou, Chengdu and Chongqing, mainly distributed in the central city of Chengdu and the eastern part of Chengdu such as Qingbaijiang and Jintang. There are also dialects, Hakka dialects and local dialects belonging to Southwest Mandarin-Xishu Pian-Minxi Pian. Today's Chengdu dialect is not the ancient Shu dialect, but the Huguang dialect formed after immigration. And influenced by the southern dialect.