If you are speaking of the present lack of available guns and ammo, i tend to place the reason for shops being sold out of those things, more to the crazy antics of the rad left!
Many people are likely jarred by seeing what the Antifa & BLM are doing to cities , without any interference by the forces we always took for granted, would protect the innocent population.
That being the case, the rad left like Obama, are very good salesmen of guns and ammo. one indicator, it appears the first guns and ammo to sell out, were the dreaded "assault" rifles and handguns, along with their appropriate ammo.
I stopped by my LGS about a month ago, looking to buy another centerfire rifle, specifically a Thompson Center bolt action or a Ruger American bolt action. in .223. The shop owner, Mark at first thought I was looking for a Ruger mini 14 ranch, and he said, "no chance"..all semiauto .223 rifles were sold out and backordered.
The fact that those rifles and the usual 9mm and .40 cal handguns are most often considered to be choice guns for self defense, would explain why they went first. I have talked to 3-4 LGS owners, and they view the sales that way also.