Despite the long development time the ERGM never worked as reliably as the older but significantly less expensive laser guided M712 Copperhead. During development, the ERGM failed several tests in which the tail fins failed to deploy at launch, rocket motors did not ignite or the electronic components did not survive the stress of being shot from a deck gun. Rising cost was another likely factor in cancellation. The unit cost of the shell more than tripled, from $45,000 in 1997 to $191,000 by 2006, reducing the projected buy from 8,500 to about 3,150 (in contrast the Copperhead average unit production price was about $30,000). BTERM is another U.S. Navy developmental round that includes GPS guidance in an artillery shell; it too was terminated in 2008 after 4+ years of development by ATK.