so where is the ammo going?
The typical route is:
Factory -> Wholesaler -> Distributor -> Retailer -> Customer.
Most of the online "direct" sales are Distributor (with the occasional Wholesaler).
This has to do with how the ammo is packaged.
ABC Factory runs off a batch of Cal..123 FMJ, that's by the pallet load--hundreds of cases, or crates of cases.
Wholesaler takes delivery and stacks it next to the JHP and SP and whatever other kind of ammo ABC makes in 0.123 caliber. They then break those (sometimes) into more saleable lots, say, ten cases of each, on a pallet.
Distributor Takes delivery of that ABC packaging, and sets it up in Retailer lots.
Retailer puts in orders by the box or by the case to fill their shelves.
At every step of this are standing orders for various sizes of "buy." So, you have to hold the delivery until the "buy" is filled; then it ships. (Picture the variety of ammo at the GS or big box store--every box on those shelves was once part of a case which was part of a pallet from somewhere.)
The other aspect is less obvious. The other days of the week when one is not in the LHS, one of the (estimated) 7 million new owners pops in and buys just one box, even at $2/round. That's one less box on the shelf.
Those new shooters bought somewhere between 14 and 21
million boxes of ammo last year. That's a bit over a million
cases of ammo. Let's suppose 100 cases to the pallet, that's 1000 pallets.
That's just the new shooters.
There's at least 4-6 times that many 'established' shooters.
Then, we had Remington ammo shut down while they sorted through bankruptcy. All while the couf either shuttered or reduced production capacity for a significant portion of the year.
I saw an assessment that the ammo factories weer running at around 10% of capacity for the first four months of 2020. Right as demand increased by 25-50% (no one agrees on that number).