Just a piece of information I received today from a gun shop owner: He said that he's been told by his suppliers that there will be very little supply of reloading components until 2023. He was told that much of the supply of components is being funnelled into loaded ammunition, and that the US market has scooped almost all of the available supply. The pandemic, the effects on the economy from the pandemic, and the public anxiety and general uncertainty about the economy and future in the US has accounted for this.
Edit.Just to add to what's noted above, I ran across the following explanation on the Free Range American website from March, 2021 (The whole article is here: https://freerangeamerican.us/ammunition-shortage/). It sums up what was told to the gun shop owner, and, although it focuses more on ammunition, I think the same factors explain the shortage of reloading components. They are in short supply in the U.S., and the little that's left over finds its way to Canada at some point in dribs and drabs. I've just reproduced the most relevant part of it below:
"The scarcity of ammunition is the result of a perfect storm that initially formed during the first quarter of 2020 as the effects of a worldwide pandemic took hold. In one fell swoop, the COVID-19 outbreak and the restrictions that came with it put the brakes on a roaring US economy. Businesses, many of which were considered financially sound prior to the pandemic, closed their doors for good. The worldwide supply chain snapped like a dry twig as we frantically searched for masks, hand sanitizer, isopropyl alcohol, toilet paper, food staples, and, yes, guns.
"Widespread civil unrest swept the nation by summer, with intensity the likes of which we haven’t seen since the 1960s. Buildings burned, stores were looted, and reports of violence and rising crime rates made national headlines. All the while, some called to defund local and regional law enforcement agencies, and several municipalities followed through. Fear of the virus, fear of food shortages, and fear of riots — real or imagined — gripped many American hearts and minds. Guns and the ammo to feed them flew off the shelves in record numbers — and continue to do so — many going to people making their very first firearms purchase. When talking to these first-time customers from behind the counter where I work, I can’t tell you how many times the conversation starts with: “I never thought I would buy a gun.”
"The storm was upgraded to hurricane status in the face of what was arguably the most contentious national election in US history. Among other polarizing political topics of the 2020 election was gun control. During the presidential campaign, Joe Biden proposed a federal gun registration under the National Firearms Act (NFA) and a $200 tax stamp for modern sporting rifles such as AR-15s, along with magazines with a capacity of 10 rounds or more. Whether these proposals will gain any traction or hold up in the courts is another question. Yet with a pro-gun-control majority now in Washington, firearms owners new and old are paying extra attention. This heightened state of awareness has created fertile ground for misinformation to take root regarding the lack of ammunition on store shelves. The most popular whoppers purport collusion between the big ammo companies to stockpile ammo and drive up demand, as well as a secret directive from the Biden administration to withhold ammo from citizens and only sell it to the military. While these conspiracy theories are certainly tasty to chew on, the truth is as bland as an unbuttered slice of bread."