A report from the Government Accountability Office (GAO) shows the Internal Revenue Service has more than 3,000 handguns and 3,000,000 rounds of handgun ammunition in its Criminal Investigation division alone.
According to the GAO, the Criminal Investigation side of the IRS also has 554 rifles, the majority of which are semiautomatic, but automatics are also included. They have an excess of 5,000,000 rounds of ammunition for the weapons, including the ammunition for the handguns.
Regarding the police division of the IRS, there are an additional 20 handguns, two shotguns, four rifles, and an additional 14,706 rounds of ammunition.