A free app for Android, by Advanced Weapon Tech.

Custom Gun Simulator 3D is the ultimate weapon-building game. Build your weapon from the ground up, customize it with different parts and attachments, and fire it in the shooting range. You can even add a red dot sight and a laser sight.

The best part is that you can build and customize your guns using real parts, and you can use all the attachments and sights that you like. There are lots of different attachments, including the standard ones like a scope, a light, and a laser, but you can also build a new one from scratch. You can also add a camo, which is a kind of sight that has a particular effect on the target.

Custom Gun Simulator 3D has many different shooting ranges with timed missions. You can choose the range and the weapons to build, and you can also choose the number of shots and the amount of ammo. The game will show you the score and the number of bullets left when you finish the mission.