The government is really stupid to buy such things. But nothing ever stops them from foolishly spending taxpayer's money.
The pistols were very simple single shot designs. They have been shown to be able to fire a few shots before they become non-functional.
Some just look like guns. Some are fully functional. The idea is like the 'Liberator' guns that were dropped into Europe during WWII. You use the Liberator to get a real gun.