Borrowed the below from another site. Interesting read on primer shortages. Might also be why powder is coming available but primers don't seem to be.
Disruptions in the Supply Chain
Demand, however, is just one part of the story. Disruptions in the supply chain have also made a big impact on the availability of primers. When it comes to ammunition supplies, bullets are easy to manufacture, brass can be re-used, and powder is generally stockpiled by companies (though perhaps not the kind you're looking for). This leaves primers, which are relatively difficult to make, as the component that causes the bulk of ammo shortages.
In the U.S., only four companies (Winchester, Remington, Federal, and CCI) manufacture primers for civilian use, law enforcement, and the military. Even under perfect circumstances, there's only so much they can produce at once, and needless to say, circumstances have not been perfect during the pandemic. People getting sick, missing work to take care of their kids, and self-quarantining – from factory workers to delivery drivers, and all throughout the supply chain – caused a lull in manufacturing this spring.
The Remington bankruptcy has had a large impact on the shortage of ammo and primers. With Remington in a state of financial insolvency for the past two years, suppliers were demanding payment upon delivery for products. Remington simply did not have the financial capabilities to have an abundance of raw materials on hand and had to shutter some of their production capacity. Barnes bullets and primers were hit particularly hard in the reloading market. With the recent purchase of Remington by Vista, there is a good chance that Vista will be diverting CCI and Federal primers that would typically go to reloaders to Remington ammunition production. Remington primer production capacity has never been great. The hope would be that Vista will place more emphasis on getting the Remington primer production capacity increased substantially and quickly. The best news coming out of this is for Barnes fans. With Sierra's purchase of Barnes we anticipate the availability of Barnes bullets to increase substantially in a very short period of time.
In 2008 we saw a huge influx of Russian primers. We are not seeing that this time as the Murom Apparatus Producing plant is only producing at partial capacity due to the COVID-19 restrictions. On top of that, there have been changes in upper management at Murom which have caused further disruptions. But, we are very hopeful that these changes will have a positive effect on production and distribution in the long run.
With import restrictions out of Russia, we do not anticipate seeing the help we had from them in 2008-2012. We had also seen S&B, Unis Ginex and other foreign brands of primers enter the market during the shortages to relieve some of the pressure, but aren't seeing that influx of primers this time around. The lack of foreign primers on the market is a major reason we believe this shortage is going to last for quite some time. We may see some help from foreign primers, but we don't anticipate the large volumes we've seen previously.