Via my uncle:
"It has been tried before. It didn't work and non-meteoric iron was used instead: 'A mass of of the Campo del Cielo meteorite of about 1,000 kg, was found in 1803 at Runa Pocita and called Otumpa, was transported via Santiago del Estero to Buenos Aires. Here an attempt was made to forge weapons from it, because there was a shortage of iron in the republic which was at war with Spain at that time. A report of the experiments in the armory by its director, De Luca, is preserved (Alvarez: 158). Two pistols with gun barrels of "Otumpa" iron were presented to President James Monroe of the United States and another to General Manuel Belgrano, but the remainder of the block was presented by the newly founded Argentinean Republic to the British Consul General Sir Woodbine Parish who, in 1826, transferred it to the British Museum where it became the first large meteorite on display.
" 'The two pistols are now on display in the James Monroe Law Office, Museum and Memorial Library in Fredericksburg, Virginia. They constitute a pair of almost identical, short-barrelled, flintlock equestrian pistols with beautiful Spanish style ornamentation. By the kind cooperation of Mr. Lawrence G. Hoes, Keeper of the Museum, I was permitted to examine one of the pistols. A tiny bled of metal was removed from the flintlock, polished and examined. The microscopic examination showed the metal to be composed of equiaxial ferrite grains, with uniformly oriented slag particles. No meteoritic materials were present. The electron microprobe study disclosed less than 0.3% Ni. Independently, Daniel J. Milton of the U.S. Geological Survey analyzed the gun barrel by spectroscopy and also found negligible amounts of nickel. The material is thus typically wrought iron with no meteoritic admixture. Perhaps the pistols were originally intended to be produced from meteoritic iron, but the weapon smith may have found his work unsatisfactory and substituted the pistils with normal wrought iron pistols. At any rate, the pistols, formerly in President Monroe's possession and allegedly made from Campo del Cielo meteorites, contain little or probably no meteoritic iron at all.' "
The portion cited by my uncle was from an article by Vagn F. Buchwald, a Danish author and former president of the Meteoritical Society.