It would be difficult for me to make this statement in NJ. What gun shops that are open are open by appointment and browsing traffic is discouraged. The local Bass Pro has been "temporarily closed", as has been the Cabelas in Delaware and Pennsylvania. Venturing into neighboring states is facing a mandatory 14 day self quarantine in the neighboring states if you venture off the Interstate.
My only barometer of ammo availability is the offerings made by the Sportsmans Guide, where I buy most of my ammo, if I buy ammo. What they show in stock:
Some revolver ammo, many old chamberings and some of the new monster magnums.
Mostly semi-auto ammo for the weaker or less popular semi-auto handguns.
A significant amount of rimfire ammo.
I saw both 41 and 44 Magnums at close to a buck a round. First time I saw Remington 38 Short Colt. Didn't see much, if any, 9mm, 40 S&W, or 45 ACP, but 45 GAP was listed as available, as was 32 ACP.
Some ammo was showing projected availability going into August.
I am very grateful that I reload, and am set up to cast virtually every handgun bullet that I shoot. I am also grateful that I had the foresight to purchase about six thousand 357 gas checks at auction last summer when they were offered at a great price.
Unless merchants impose an unpopular daily limit, I fear we will see extended shortages due to panic purchases/hoarding when stock starts to replenish. I hope that I am wrong!