that only require the range be dialed in. These are tuned to both a specific class of rifle and specific ammunition. Every bullet type and load will have different ballistics. .308 Federal 175 grain (11.3 g) BTHP match shoots at . Zeroed at , a 16.2 MOA adjustment would have to be made to hit a target at . If the same bullet was shot with 168 grain (10.9 g), a 17.1 MOA adjustment would be necessary. Shooting uphill or downhill is confusing for many because gravity does not act perpendicular to the direction the bullet is traveling. Thus, gravity must be divided into its component vectors. Only the fraction of gravity equal to the cosine of the angle of fire with respect to the horizon affects the rate of fall of the bullet, with the remainder adding or subtracting negligible velocity to the bullet along its trajectory. To find the correct zero, the sniper multiplies the actual distance to the range by this fraction and aims as if the target were that distance away. For example, a sniper who observes a target 500 meters away at a 45-degree angle downhill would multiply the range by the cosine of 45 degrees, which is 0.707. The resulting distance will be 353 meters. This number is equal to the horizontal distance to the target. All other values, such as windage, time-to-target, impact velocity, and energy will be calculated based on the actual range of 500 meters. Recently, a small device known as a cosine indicator has been developed. This device is clamped to the tubular body of the telescopic sight, and gives an indicative readout in numerical form as the rifle is aimed up or down at the target. This is translated into a figure used to compute the horizontal range to the target. Windage plays a significant role, with the effect increasing with wind speed or the distance of the shot. The slant of visible convections near the ground can be used to estimate crosswinds, and correct the point of aim. All adjustments for range, wind, and elevation can be performed by aiming off the target, called "holding over" or Kentucky windage. Alternatively, the scope can be adjusted so that the point of aim is changed to compensate for these factors, sometimes referred to as "dialing in". The shooter must remember to return the scope to zeroed position. Adjusting the scope