The 9mm was gravitated to because of its lower ammo cost, higher capacity in pistols and much lower recoil and longer weapon service life. Advances in expanding ammo also nullified any advantage the 40 may have once had and if it did it was very little.So the FBI dropped the 40 SW and then of course people no longer were interested. Everything is high cap 9mm
Yet, it seems many are now getting into 10mm?
I don't get it?
Also 9mm service pistols have a longer life span before major repairs or replacement is needy compared to the 40 S&W. Also the .40 S&W was not safe when used with high pressure loads and heavy bullets because lacking any airspace in the cartreige resulted in catastrophic explosions when bullet setback occured. The ammo factories quietly cut back high pressure loadings with the 180 grain loads and then everyone gravitated to the 160 grain loads that have higher velocity but less penetration. There is no problem with heavy bullets in the 9mm as high pressure loads in the 124 grain bullets were perfected by the Germans after WWI when the 115 grain bullets were proved to lack sufficient penetration. Decades late the U.S. Miami shootout once again proved that the 115 grain bullets often lacked sufficient penetration and that the heavier 125 grain bullets were the way to go.
As far as a resurgence of the 10mm that is a niche cartridge used by hunters not by people who carry weapons everyday for protection or police work. Its larger size and heavier weapon weight and high price per round and heavy recoil and lower capacity will never make it as popular as the 9mm. On the other hand hunters will not want to use a .40 when the 10mm is available.
Strange that history repeats itself but back in the days of the Wild West the .40 cal pistol cartridges were popular for a while but eventually were replaced because people either wanted bigger or smaller pistol cartridges than the .40 and the .38 caliber eventually dominated police and military pistols before the advent of the auto pistol.
The .40 S&W is headed for eventual extinction but how soon is anyone's guess but History is being repeated as lower and lower sales of the .40 show the handwriting is on the wall.
