Not government hoarding. Despite some staggeringly large ammunition buys from HHS. This from American Rifleman, the NRA magazine. The shortage is real, at least up here the shelves down at Cory's Sport Shop, are empty of all but the most common calibers.
Although HHS has placed some massive buys, these are multi year contracts, and according to American Rifleman, the quantities are about what the agency has bought in past years. The real increase is in the number of American gun owners. Particularly striking is the increase in woman gun owners. The increase in demand is real, and you can see it in the revenues from the federal ammunition tax. That's gone up and up and is showing no sign of slowing down. The number of federal instant background checks has also grown significantly, supporting the ammunition tax data.