The K2 automatic rifle is the Default Primary Weapon of Operation 7. It comes with a good amount of extra ammo (about 5 extra magazines). When you go to look at your weapons, you won't find the K2 under your possessed weapons, so you cannot add a scope or make any modifications to it. Once you create your first weapon, it will replace your K2.
Most players use this weapon first before buying anything, therefore they earn more money and they're able to save up for better items after ranking up. What's good about this rifle is that it is pretty average on accuracy, control, and power, and definitely because it's free. There is a way to get this weapon back after purchasing a weapon. What you need to do is to buy a 3 day weapon slot and purchase any weapon. Now here is the trick,you have to have the weapon that you purchased equipped when the 3 days are over. When you do this it will register as you not having a gun, thus giving you the K2 back. However, if you equip any other primary gun while you have the K2 you will have to re-do the process to regain the K2 once again