The ammo companies could invest in equipment and pay for it in a short time IMO.
Oh? Manufacturers have gone as far as they can go with their existing production lines pushed to 24/7 operation. But they can't simply create new production lines/plants for .22 rimfire out of thin air, and they can't pull resources from some other production line (say 9mm, for example) because centerfire and rimfire production are so different there's no commonality in the machinery.
So we have heard news that the various manufacturers are working toward increasing their production capacity, but that takes time -- often years. "Increasing production capacity" may mean everything from having a piece of land surveyed and purchased, planning/zoning, impact studies and stormwater management plans, and electrical distribution systems routed in, wastewater treatment, industrial engineering for the new production lines, machinery spec'd, machinery sourced (uncommon equipment, now suddenly in high demand, itself), personnel hiring, sourcing new streams of raw materials (already over-extended), etc., etc., etc., etc.
They can't just "turn it up to ELEVEN!" Even running at near 100% will end up being problematic. Actually taking steps to change their total capacity is an enormous undertaking.
So these companies have had to predict what's going to happen with the market, finally decide that this panic is long-enduring enough* to actually support whatever new capacity they decide to bring on, and then act on that decision which will probably take in excess of a year -- maybe two! -- to bring about.
* -- Not capitalizing on a boom is bad. Spending a year or more and hundreds of millions of dollars to build a new plant, and finally opening just as folks finally decide they've got enough ammo stacked away, the political situation changes, the pressure's off, and the bottom falls out of the market would be MUCH worse. Companies could go bankrupt over a badly played action like that.
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But everyone on teh interwebz knows that these greedy slacker ammo companies aren't doing anything to meet the demand because they're making a killing and are perfectly happy to let us shooters starve for ammo just so they can jack the price up, and anyway George Soros owns them all and is tightening down the screws on the industry so we don't have any more ammo to buy, because Obama told him to... yadda yadda...