My answers would be quite different if I got to pick three, not rate the three the OP listed.... 1. A consistent FPE level to drive the pellet, as varying velocity cannot be overcome except at close range....2. A good barrel, and finding a pellet that works with it, as if the pellet doesn't fly straight that likewise cannot be overcome....3. Holding and firing the gun in a consistent manner (including ergonomics and trigger), as even he most accurate gun in the world can't hit a target unless you do your part....Unfortunately, in the real world, item 3 usually turns out to be the limiting factor, but that's not really the gun's fault....Bob