The Sledgehammer in MW3 and Warzone can be unlocked by completing the Season 4 Week 5 challenges. It is a Melee Weapon that joined the games in the Season 4 Reloaded update. The weapon features a 20-pound carbon steel head that can be swung, pole-butted, and used for overhead smashes to stop foes dead in their tracks. Needless to say, it is a force to be reckoned with.Fortunately enough, it is free, and you won't even have to grind through the Battle Pass to get this item. All it asks of players is they complete five simple challenges. This article will offer a closer look at how you can unlock the Sledgehammer in MW3 and Warzone.How to get the Sledgehammer in MW3 and Warzone?To unlock the Sledgehammer in MW3 and Warzone, you must complete any five of the seven Season 4 Week 5 challenges in Multiplayer, Zombies, or Battle Royale.The following are all the challenges in MW3 and Warzone Season 4 Week 5, as presented in-game:MW3 MultiplayerGet 30 Operator Assists - 2500 XPGet 15 Operator One Shot One Kills with Recommended Shotguns - 5000 XPPerform 3 Finishing Moves on Enemy Operators - 7500 XPGet 2 Operator Fury Kills with a Recommended Weapon - 10000 XPGet 10 Operator Kills with the Gun-Butt of a Recommended Weapon - 5000 XPGet 12 Operator Kills with Claymores, Proximity Mines, or C4 - 5000 XPGet 3 Operator Melee Double Kills - 7500 XPNote: Fury Kills require you to get four eliminations in quick succession.MW3 ZombiesComplete 10 Contracts - 2500 XPGet 250 1 Shot 1 Kills with a Pack-A-Punched Recommended Shotgun - 5000 XPPerform 5 Finishing Moves on Mercs - 7500 XPGet 5 Rapid Kills 30 times with a Recommended Assault Rifle - 10000 XPGet 75 Kills with the Gun-Butt of a Recommended Weapon - 5000 XPGet 75 Kills with Claymores, Proximity Mines, or C4 - 5000 XPGet 10 Kills without being hit 20 times with a Recommended Melee Weapon - 7500 XPWarzoneIn Fortune’s Keep, Get 10 Operator Kills in the North Region (Gatehouse, Keep, Terraces) - 5000 XPIn Fortune’s Keep, Get 10 Operator Kills in the East (Konni Outpost, Lighthouse, Pier, Winery) - 5000 XPPlace in the top 10 5 time(s) - 1000 XPOpen 50 Loot Caches - 2500 XPIn Fortune’s Keep, Get 10 Operator Kills in the West (Graveyard, Overlook, Town) - 7500 XPIn Fortune’s Keep, Get 10 Operator Kills in the South (Ground Zero) - 7500 XPComplete 10 Contract(s) - 5000 XPThat's it. Once you have completed any five challenges in one of these modes, you will unlock the Sledgehammer in MW3 and Warzone.Check out our other Call of Duty articles:Every weapon buff and nerf in Warzone Season 4 ReloadedAll new events in MW3 and Warzone Season 4 ReloadedAll new weapons in MW3 and Warzone Season 4 Reloaded