At the ammo store I am occasionally asked my opinion of the .40S&W as far as how much is it tanking, will most manufacturers continue to produce it, etc… Most people seem to know that this caliber is no where near it’s height of popularity back around 2000 - 2005, but it’s hard to gauge exactly where it ranks in the top-ten of pistol calibers. Obviously 9x19 is first, then .45 auto. .40S&W had been the #3 rank for the past 20 years it seems like, but I would rank .38spl, and even 10mm of late, as being right there with it in terms of ammo buying habits. I think what will keep the .40S&W in the top 5 for many years to come is the sheer volume of pre-owned pistols out there which can be found for relatively decent prices at gun stores and pawn shops. Lots and LOTS of Glock & Taurus rigs abound in .40S&W from shooters who have gone back to either 9mm or .45acp.
One thing which really brought home to me how far the .40S&W has fallen is that while the distributor Ellett Brothers is disintegrating in bankruptcy, their ammo inventory has dwindled from 3000+ skus, down to under 140 today, and the .40S&W is the most left-over of any caliber. They can’t even give it away to their FFL buyers (shops) even though the prices are rock-bottom.