New Perk idea for Mc-War

Well one thing I hate while playing Mc-War is that I will take the wrong gun. So to make up for this maybe there can be a new perk. This perk would allow you to change guns once during a game if necessary. Obviously some people will use it to get more ammo, so to combat this all that needs to be dome is make the player's current ammo convert to the new required ammo with the amount the player had before using the perk. Sorry if the last sentence was a little confusing to read.