How to get Cerberus sniper rifle
In order to get the rifle, you must go to the Fort Vaullery Imperial Base. This will happen when you reach chapter 6. Also, you can always return to the base and pick up the rifle, as you will unlock the Imperial Base for the rest of the game. So even after you’ve completed the whole story, check back to the base to find this hidden weapon. It is located in a small building in the northeast of the base.
This is the only sniper rifle in Final Fantasy 15, so make sure you get it as soon as you can. It makes many battles a lot easier, since it enables precision targeting. Note that Noctis is the only character in FFXV who can wield this gun and that Prompto, unfortunately, cannot equip it. You should use it to break your opponents at range and to soften them up before you engage them. To use the scope of the rifle, hold R1 and Triangle (RB and Y on Xbox One), but note that when you are outside of combat, you cannot use it.
Although it is not the best weapon of choice in close combat, start the fight with it as soon as you get in range (its range is 100 feet). Break the opponent’s guard, as it will give you some major bonuses depending on the type of the enemy you are fighting. The effect will last during the whole fight. Its base damage is 156, but once it’s scoped, you can deal some critical shots and aim for the vulnerable parts of the enemy’s body for higher damage.