Joseon Empire's Military Geek Emperor

Choi Seong-jun, a 21st-century military enthusiast, has been reincarnated as Cheoljong, the 25th king of Joseon. But of all people, why did he have to be Cheoljong, one of the four worst monarchs in Joseon's history? However, a Cheoljong reincarnated from a 21st-century military buff is different. Let's replace the Joseon army's pathetic matchlock muskets with new models and build powerful cannons. The way to become a winner in the era of imperialism is...? From this moment on, the Joseon Empire of the military-maniac Emperor begins!!