Despite Black Ops Cold War catching the spotlight for its new weapons, Call of Duty: Warzone and Modern Warfare have secretly added a pair of guns of their own. However, players won't be spotting these in the main menu. Instead, those desiring these weapons will need to partake in secret challenges in Modern Warfare to have them in the battle royale, as well. So, here's what you'll need to do to own these excellent bullet sprayers. Unlocking the CX-9 SMG Image via Activision The CX-9 may look like a Kilo 141, but this heavily damaging SMG is a reincarnation of the speedy MAC-10. To own and customize the gun, players will need to complete its dedicated hidden challenge: Score two longshot kills with an SMG across five different Modern Warfare matches. If you don't own Modern Warfare or simply want to try the gun out, the CX-9 Serac blueprint is finally showing up in Warzone through loot boxes. This Rare-variant blueprint is a tough find, but most users are discovering the gun in\u00a0the battle royale's newest bunkers. Unlocking the Sykov pistol Image via Activision For those who've played the original Black Ops, you may remember this powerful secondary as the Makarov. Now going by Sykov, the weapon can be obtained in either Multiplayer or the battle royale when earning at least four pistol kills in five different Modern Warfare matches. Those only playing Warzone can find the Sykov in the game's Plunder mode, but unfortunately, they cannot own or customize the weapon if the challenge isn't completed.