The Official designation of this artillery projectile is a 155MM cannon launched, fin stabilized, terminally laser guided explosive projectile used against hard targets. The article that I read listed the maximum range of this projectile as 16,000 meters. I'm not so sure about the range as it is listed. This projectile was new when I left military service but I seem to remember a maximum range which was much more. 

The copperhead operates by detecting a laser signal and guiding itself to it. Once it acquires the signal the fins will adjust themselves to aerodynamically guide the copperhead to its intended target. There are other variables which must be accounted for to make the copperhead function correctly. The observer must operate the laser from within certain parameters to give the copperhead enough time to change its direction. The artillery crew that fires the round must also meet certain operational guidelines in that they must fire it from an area which will also give the round enough time to change direction.

This artillery projectile was first used in an operation during Operation Desert Storm. It was a new weapon then. We had to train up on it during the time that we were deployed there before the war began. Our General was anxious to use it in combat and he ordered one up the first chance that he got. I could create a custom military ring to tell my story of the first time that this round was used. It was a doozy because it required a lot of people to be moved a long way. The round was used to blow up a few Iraqis in a building. A few bullets could have been used to do the same thing for much less money.