It looks as though Infinity Ward has hidden a few extra weapons in Call of Duty: Modern Warfare Remastered. In a post on Reddit, /u/Semyel gave extensive notes on the recent discovery. He explained how a friend of his was looking through some of the game’s files on the PC version of the game when he came across references to a melee shovel and other weapons hidden in the game. Most of these weapons were featured in older Call of Duty games.
Semyel noted that, “A few days ago I tried changing the weapon index in the game with cheat engine which got me a a few of the weapons but not the shovel and some didn’t work correctly.” He then states that thanks to the help of other players, he eventually got the melee shovel to appear in the game.
On the post, Semyel has posted links to videos showing off some if these weapons, but these videos have since been taken down by Activision. Semyel believes that these hidden guns existed at some point during the development cycle of the game, but where probably dropped due to feedback from for the supply weapon drops that were featured in Call of Duty: Black Ops 3.