In the worst days of the Iraq War, the Pentagon launched a media campaign designed to convince the world that Iran was smuggling arms to Iraqi insurgents. Some of the claims strained credulity, such as the idea that Iran would supply Sunni insurgents fighting against its Shia allies. In particular, Iran was supposed to be the main supplier of deadly EFPs, or explosively formed projectiles. To some, these claims were alarming evidence of malevolent Iranian intentions. To others, they were a transparent effort to blame US failure on Iran.
Turns out that the latter were right:
The caches that included Iranian weapons thus represented just 2 percent of all caches found. That means Iranian-made weapons were a fraction of one percent of the total weapons found in Shi'a militia caches during that period.
The extremely small proportion of Iranian arms in Shi'a militia weapons caches further suggests that Shi'a militia fighters in Iraq had been getting weapons from local and international arms markets rather than from an official Iranian-sponsored smuggling network.
Left out of the list of Iranian-made weaponry were 350 armour-piercing explosively formed penetrators (EFPs) found in Iraqi weapons caches. Despite the lurid claims of US officials, the task group couldn't ascribe an Iranian origin to a single one...Iranian equipment is less reliable and more expensive than Eastern Block materiel that flooded the region after the 2003 invasion -something which a certain imprisoned international arms dealer, ex-CIA and ex-US military contractor and supplier to despots and terrorists, Viktor
Bout, may well know a fair bit about. It's a buyer's market and the Iranians are seeing market forces exclude their produce, with the exception of simple artillery rockets. They're more expensive than the Pakistani arms bazaar's copies coming down the old Silk Road routes and far less effective than easily available and comparatively-priced black market US weapons too.