Anzio 20mm Anti-Material Rifle – Designed to be used against light vehicles and equipment
One of the very few options in the Western world, and perhaps the only one in the USA, if you want a new-build rifle in a caliber bigger than .50 cal.
Each rifle is hand built to order, they cost $13000-20000 and weigh 59-130lbs depending on configuration. They use match grade hand-lapped barrels and can be chambered for 4 calibers
20×110 Hispano Suiza
20/50 which seems to be their own custom load