Here is what the 20mm sniper rifles the FBI ordered looked like:

And here is the text from the purchase order:

The FBI intends to procure the following items:

Magfed 20mm Rifle with Belgian Camo Overcoat finish. Includes bipod, brake, handguard, free floated barrel and case (Qty: 1 each)

Magfed 20mm Rifle with Navy NWV Camo Duracoat finish. Includes bipod, brake, handguard, free floated barrel and case (Qty: 1 each)

Non-firing bolt assemblies (Qty: 2 each)

Extra magazines (Qty: 4 each)

Suppressors in 20mm (Qty: 2 each)