The U.S. Army has ordered another 216 Excalibur GPS guided 155mm artillery shells. This batch will cost $70,000 each, which is down from $150,000 each when Excalibur first entered service in 2007. Ultimately the price is to get down to $50,000, which some say has already been achieved if you don’t count development costs.
Early on the army found that GPS guided shells were more successful, but less frequently used, than anticipated. So they reduced orders for these weapons. There was less demand for Excalibur shells largely because other precision munitions often take out targets before Excalibur gets a chance to. There’s a growing number of other GPS (or laser) guided weapons available. The GPS guided MLRS (GMLRS) rocket has been especially popular. And the army uses a lot of laser guided Hellfire missiles, fired from AH-64 helicopter gunships or UAVs. In addition to the reduction in Excalibur production, the army cut orders for GPS guided 120mm mortar shells (introduced in 2011) after a year of use.
Excalibur is being displaced (and may be replaced) by the new PGK (Projectile Guidance Kit) shells. PGK is actually a large fuze that screws into the front of a 155mm or 105mm shell. This longer fuze contains a GPS and small fins to guide the shell to a precision hit. It is less precise than Excalibur. That is, the PGK will ensure that the shell lands within 30 meters of the target. If it does not hit within 150 meters, PGK deactivates and the shell does not explode. An unguided shell will normally land within 300 or more meters of where it is aimed. An Excalibur shell lands within 10 meters of the target but PGK costs only $3,000 each and turn any shell into a GPS guided one. The army sent the first PGKs to Afghanistan in 2013, after successful testing in the United States. The big question was how important will the troops find the accuracy differences of Excalibur and PGK.
It turned out that the troops preferred the slightly more accurate and reliable Excalibur over PGK but found PGK could do the job, just not as well as Excalibur. To further distinguish Excalibur the manufacturer has developed a dual mode version that all allows for use of a laser designator. This provides even more accuracy, usually putting the shell within a meter or two (less than seven feet) of the aiming point. Excalibur is often called in when precision is the main requirement and this dual mode version provides the greatest accuracy available with any guided munition.