FGR - 17 Viper The FGR - 17 Viper was an American one man disposable antitank rocket which had slated in the 1980s to be the replacement for the M72 LAW , but was canceled shortly after production began due to a major public scandal resulting from massive cost overruns and safety concerns , as well as a mistaken belief by the U . S . Congress and the American public that the term " light antitank weapon " meant a weapon that could defeat any hostile armored vehicle threat from any firing angle ( including frontal shots against the Soviet Union ' s new T - 64 and T - 72 main battle tanks ) . Program history . Start of the program . The Viper program began in 1972 as a study to replace the M72 LAW . In 1975 , a program designated ILAW ( Improved Light Antitank Weapon ) issued a request for proposals to the defense industry , and in 1976 after studying the various industry proposals , the U . S . Army designated General Dynamics as the prime contractor , changing the ILAW program name to " Viper " . The main requirements for the ILAW / Viper program was for a disposable weapon in the same weight and size category as the M72 LAW , but with major improvements in accuracy , safety and penetration and without a major increase in cost per round over the M72 LAW which it was to replace . Poor requirements statement . When the ILAW requirement was first issued , the Army wanted an individual antitank weapon with such a low cost that it would be as common in infantry units as the hand grenade was . All these requirements , which included items contradictory to each other , proved to be too great a hurdle for General Dynamics . This resulted in subsequent issues that led to highly publicized congressional inquires into a classified GAO report which stated that the Viper " . . . barely meets the " low end " of the Army ' s requirement . . " and furthermore concluded " . . . Viper did not demonstrate any significant superiority over the M72 LAW . " Over - optimistic statements by the prime contractor . Journalists soon discovered that when the prime contractor was named in 1976 for the Viper program , General Dynamics had told the Army that when mass production for the Viper was reached , the cost of Viper would only be $ 78 . 00 per round before inflation . Despite the negative publicity , the Army decided to continue the Viper program and make improvements . In December 1981 , General Dynamics was awarded a $ 14 . 4 million dollar contract to start production for 1400 Viper rounds . Safety issues . Shortly after this contract was issued , there were also reports of safety problems with the first production lot during field evaluation tests by the U . S . Army . Test firings had shown Viper rounds to have a safety problem with its fuze system that caused the warhead to explode shortly after launch . One report detailed an accident at Fort Benning , Georgia where a helicopter pallet of Viper rounds were found to be damaged by static electricity . Scandal and congressional intervention . In February 1982 , in a move that took even the strongest supporters of the Army by surprise , the Army issued a second contract worth $ 83 . 7 million for 60 , 000 more Viper rounds . Following the anger caused by the letting of this second contract and because of the earlier GAO report on the Viper , massive cost overruns , and then the safety concerns revealed in the Army ' s evaluations , in December 1982 Senator Warren Rudman ( R - NH ) inserted an amendment into the Army ' s funding bill . This amendment deleted 69 % of the Viper funding and further mandated testing of available light antitank weapons which were already in production , including non - U . S . models , with a report due back to Congress in 1983 . End of the program . About this time , General Dynamics made the decision not to compete in the tests mandated by Congress , because of the Army ' s demand for a fixed price contract on any future Viper production lots that were to include safety improvements . This meant that after the Army had spent over $ 250 million on a M72 LAW replacement since 1975 , the Viper program was at an end . With General Dynamics decision to refuse a fixed price contract request , the Army announced in September 1983 that it was canceling all contracts for the FGR - 17 Viper . Two months later , the testing mandated by Congress found the Swedish designed AT4 the most suitable off - the - shelf option to replace the M72 LAW . The AT4 did not meet every requirement , but it was the only one to meet most of the requirements . Congress agreed and funded that weapon as the future M72 LAW replacement .