From The Washington Examiner:

In a Senate Appropriations Committee hearing, ATF Director B. Todd Jones said all types of the 5.56 military-style ammo used by shooters pose a threat to police as more people buy the AR-15-style pistols.

“Any 5.56 round” is “a challenge for officer safety,” he said. Jones asked lawmakers to help in a review of a 1986 bill written to protect police from so-called “cop killer” rounds that largely exempted rifle ammo like the 5.56 because it has been used by target shooters, not criminals.

So the problem isn’t M855 but all 5.56 ammo? Sounds like they want to ban all ammunition.