My own theory is that the big retailers like Walmart are not sure what's going to happen with this Administration and are taking no chances on being caught on the "wrong" side of any Obama/Pelosi/Reid decree on ammo, and are not adequately restocking right now, instead adopting a "wait and see" attitude.
So, there may be at least a grain of true in your old-timer's explanation.
I live in southern Adams County, Pennsylvania, which is very rural and very pro-2nd Amendment, and I've noticed that all four of our local Walmarts (Gettysburg, Waynesboro, Hanover, and Chambersburg) have not restocked in weeks or even months. About all you can get there is .22 and 12-gauge shells.
I remember hearing a couple years ago that wal mart was phasing out firearms sales starting in some areas first but eventually including most areas. Seems they were concerned about the liability related to selling firearms.
There may be some pressure by the government on big retailers of firearms as well. Ammo stamping isn’t law anywhere yet and won’t be so i wouldn’t think mfrs are holding back when opportunity is abundant.
also a shortage of metals, including used empty casings for reloading. Add to that the demand thanks to the firearms salesman of the year Odooma. Best advice is to stock up every chance you get. A box a week isn’t a budget breaker.
But when its gone, it’s gone.