The Army failed to properly test a critical component of body armor and can’t say for sure that 5 million pieces of the bullet-stopping equipment offer sufficient protection for troops. Those are the findings contained in a new report [PDF] by the Pentagon’s inspector general.

Tests for extreme temperature, altitude and weathering were “routinely” eliminated or tweaked for the ceramic plates inside body armor, which are a “significant part of the soldier’s protection system," the report said. It looked at testing records for $2.5 billion in contracts awarded to armor manufacturers between 2004 and 2006. The inspector general did not conduct independent testing.

The Pentagon also ceded too much authority to the defense contractors, the report concluded. Contractor employees performed “inherently governmental functions” such as evaluating test results to decide whether to accept or reject the products.

The Army responded that it has adopted the report’s recommendations and improved the process by which it tests body armor. Last year, it adopted a standard testing protocol that’s being used across the Defense Department. “The U.S. Army conducts rigorous and extensive testing of body armor to ensure that it meets U.S. Army standards and is safe for use by Soldiers in combat,” it said.

But the report's findings are the latest in a series of revelations about inadequate testing and problematic procurement for body armor.

In the early days of the Iraq war, after initially limiting the distribution of new bulletproof armor to soldiers on the front lines, the Army reversed course and scrambled to buy them for all troops in Iraq. But those orders took several months to get to the troops, even while U.S. allies that purchased body armor received their orders in just 12 days.

Then came a scathing 2006 Pentagon report, which found that of the U.S. Marines in Iraq killed by shots to the torso, at least 80 percent could perhaps have survived if they’d had extra body armor protecting their sides. That sent off another scramble by both the Marines and the Army to send over additional armor. The report also prompted calls from lawmakers for a review by the Pentagon’s inspector general.

In a subsequent 2009 rep­­ort [PDF], the Pentagon’s inspector general identified testing flaws in one order of ceramic inserts and recommended that the Army recall more than 16,000 of them. The Army maintained that the gear was safe but issued a recall anyway. That same year, the Army also decided to test the armor in its own laboratory instead of using private labs.

Two more reports this year build on those 2009 findings, expanding the inquiry to a total of 13 contracts. In addition to the latest report on the seven contracts for ceramic inserts, another report in January found that the testing done on 1.2 million outer vests for body armor—six contracts worth $434 million in all—also fell short of what was required [PDF].