They sell to retailers and some web orders. They try to allocate it.
A lot of the retailers have been taking lists from customers, or more "on the downlow," the dudes in the gun/ammo department tell their buddies when the shipments come in. End result is that when retailers get their shipments, they are gone in minutes, often due to "friends of friends" getting advance notice.
These retailers get large shipments, not just a half dozen boxes. I was there in March and saw how much of ammo and components were coming off the lines. It was crazy to see that much. And the orders being sent were pallets of product, not small boxes. They do have an allocation that goes to smaller gun stores that was also getting filled. The pallet in the pic below was one of many pallets going to a large retailer that day.
View attachment 228340
Say they were doing a run of 7mm Rem Mag and they produced 20,000 rounds on that run. A large portion would go to the big retailers who are their largest customers, say Cabela's, Midway, Bass Pro, SW, etc. Then a smaller portion was moved to the next bins for filling orders from smaller gun shops. The last of it would be allocated to online orders, where once they had 200 boxes available, they would notify customers that it was in stock, usually selling out immediately on their website.
So to answer your question, they don't sell to hoarders. They sell to their customers, both retailers, distributor groups, and direct sales. The fact that none of it can be found at stores is a function of demand far outstripping supply, and how some of the retailers have their own ways of letting people know when it is in stock.
I was in Bob Ward's at Bozeman the other morning. I was surprised how much fresh Nosler ammo and components were on the shelf. Not sure how long it lasted, but it was the most I had seen in a couple years.