http://www.thepoliceloophole.com/
Some notables:
Barrett
Cheaper than Dirt
MidwayUSA
Larue
Bravo Company
Spikes Tactical
CMMG
Top Gun Supply
There are some states, counties, cities, and municipalities in our great nation that fail to allow their citizens to fully exercise their right to keep and bear arms with restrictions such as magazine capacity or types of firearms that are widely available to citizens of other states, counties, cities, and municipalities. However, these government entities do not place these restrictions upon their own employees, such as police officers.
What is this list?
This is a list of companies that have taken the step to publicly announce that they will not sell items to states, counties, cities, and municipalities that restrict their citizens rights to own them; therefore closing the "police loophole" themselves.
Some notables:
Barrett
Cheaper than Dirt
MidwayUSA
Larue
Bravo Company
Spikes Tactical
CMMG
Top Gun Supply