A new report from Reveal has found that parts for assault weapons are being regularly sold on eBay, despite the online marketplace banning these items. The site uses automated word filters and a manual report system to spot infringing auctions, but these methods are proving ineffective, say Reveal. Sellers can avoid them with a number of techniques as simple as putting spaces in the names of gun parts manufacturers and simply not mentioning that a part can be used to construct an assault rifle.

"The buyer has to know what he's looking for."

"The buyer has to know what he’s looking for, and the seller has to be careful to not advertise that it fits an assault weapon," Ried Bridges, an eBay seller who deals in AR-15 parts, told Reveal. "If you have a part that’s compatible with a number of weapons platforms and you don’t mention that one of them is an assault weapon, my understanding is that you are good to go."

Reveal's investigation found a number of assault weapon parts for sale, with the "only missing piece of the gun" being the lower receiver. This is the component that contains core mechanisms like the trigger, and is what legally constitutes a firearm in the US. Buyers can easily purchase it from other websites, or even use equipment such as computer milling machines to make their own. Many of the rifle parts discovered for sale on eBay in Reveal's investigation were for the AR-15 — the civilian version of the US military's M-16, and the gun used in the Sandy Hook school shooting in 2012.

ebay says it takes "appropriate action"

Kari Ramirez, a spokesperson for eBay, told Reveal that eBay's policy was based on Californian law, some of the strictest in the country, and that the site always took "appropriate action" against infringing sellers. However, Ramirez refused to reveal how often eBay's filters find assault weapon parts. "This is our secret sauce," she said, telling Reveal that people were always trying to get around the filters. "We don’t want people going and trying to figure these out."