Gun writer Ronaldo Olive sends us photos of a .50 cal sniper/anti-materiel rifle captured in a drug raid. He says:

This .50BMG rifle has just been seized in Rio de Janeiro by crack BOPE (Batalhão de Operações Policiais Especiais) Military Police troops in he possession of a group of drug dealers, but I have been unable to identify it for sure. The stock appears to be one marketed by ArmaLite for its AR-50. Any suggestions? Thanks.

The rifle looks very similar to an Armalite AR-50, even being marked “Armalite AR-50A1” but is clearly distinct, having a magazine well, a different barrel shape and muzzle brake, different finish, different rail, and other details. A photo of an Armalite AR-50 is below, for comparison:

Can anyone identify the rifle?

EDIT: Ronaldo sent us a clearer picture of the fake markings on the rifle’s receiver: