I like the way you think, but it would really take a marketing Einstein to convince the ammo buying masses that MORE POWAH is not what they should be shopping for. Especially given that is the reason most of them chose the .40 over the 9 in the first place.It's a valid premise, and it cuts to the core of why I'm such an ardent .40-basher in the first place. There's enough mass and energy potential in the .40 IF YOU USE IT RIGHT, and the designers of the round really didn't. The .40 grew out of an era with lots of obsession over foot pounds and energy transfer which were both largely debunked by the time the .40 was just starting to stock the shelves. That's certainly why it commonly gets loaded at "Formula 1 compression ratios" with bullets that open very large for their starting diameter. The standard training and duty loads we used were 180 grains at about 1000 fps. They would have done very well with 900fps and a little bit less expansion on the bullet to improve the penetration - slightly - to get it up into the deeper half of the FBI's "ideal" 12-18" range. The .45 bullets could do with a bit of the same treatment - the .90 to 1.0 caliber mushrooms are impressive to look at, but they aren't very deep divers.
The irony here is that has them all ending up at about the same place. All three cartridges as they currently exist are delivering something close enough to 400 foot pounds as makes no difference (if you're into that), and all three of them in FMJ format can penetrate A LOT more than we need them to - plenty of energy to manipulate to our liking. A series of well-engineered duty loads for the trio would expand to between .65 and .85 caliber, and stop in about 15"-17" inches of bare gel.
My gripe with the .40 as it has been loaded (and many of the guns it was loaded in) is that it accelerates the wear and compromises reliability of equipment sooner without bringing anything extra of use to the party. Never mind the bashing and whiplashing on the "hard parts" - if you have to keep changing recoil and mag springs just to keep the timing of round feed workable (especially considering varying sizes of shooters or their grip on the gun being compromised by the situation), while the 9mm versions of the same stay in tolerance and keep chugging on practically forever, the system needs some help.
Due to the foot-pounds/energy-transfer mania of the late 1980's, the designers of the .40 were trying for 10mm Minus P, and we're now coming around to the conclusion that we'd not experience any terminal performance loss by using a properly constructed "10mm Double-Minus P". We're also realizing that we'd be picking up some significant benefits in shooter performance and weapon longevity as well. That this cartridge already exists in the form of the modern 147 grain 9mm duty load is the reason for the .40's current decline - mainly on an institutional scale, but the commercial side is following.
Now, all that said, making the above adjustments to the .40 bullet designs and pressure levels would be a GREAT move for anybody that's retaining a stake in the round. The reality is that we're seeing fewer new guns made for it (ESPECIALLY in compacts), discontinuance of some of the old, and dialing back of spare parts production for that which is out there. Beating your guns up with the ammo concepts of yesteryear makes little sense. Might be worth lobbying the ammo companies to see reason.
Along similar lines, it might be worth lobbying the various action pistol competition disciplines that "making major" to maintain differentiation between the "more effective" .45 and the "less effective" 9mm is an outmoded concept. It may need to be adjusted somewhat to ensure the game is played with tactically-effective power levels and keep out the gamers with their muzzle-braked .22 Shorts, but as it has been traditionally measured, it only really matters to the bowling pin guys.