Get the M16A4 :


/setblock ~ ~1 ~ minecraft:standing_sign 0 destroy {Text2:"[{\"text\":\"\\u00a7c\\u00a7lRight click on me to get the item\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/give @p bow 1 0 {Unbreakable:1,HideFlags:6,display:{Name:\\\"\\u00a77M16A4\\\"},AttributeModifiers:[{Slot:\\\"mainhand\\\",AttributeName:\\\"generic.attackDamage\\\",Name:\\\"generic.attackDamage\\\",Amount:-10000,Operation:0,UUIDLeast:1567582123,UUIDMost:1567582123}]}\"}}]"}