Let me clarify.....the 40s&w can be purchased from many manufactures with 155 or 180 with 500+ftlbs of energy. That is about what my 10mm 180jhp reloads I used for whitetail. They worked great. The 10mm in the grand scheme is too limited when you need to find commercial loads like now. You can go into any store and find 40 like you can 9mm. Forget about what the 10mm uses to do when it was introduced because only boutique brand will load them that hot anymore. Your major ammo companies full power 10mm are like the Winchester 175jhp Silvertips. These are also a well proven hunting round. Look them up and you will see they are the goto round for most 10mm hunters. Finally, 10mm fps specs are a mostly a bunch of liars. I have choreographed just about every commercial 10mm round and just about all fall short (some really short) of their advertised specs. 40S&W have been much more accurate on their reported speed out of commercial handguns that you would actually own like a Sig or Glock and not a test barrel. This also closes the real world gap between the two calibers.
Yea I have hot 10mm reloads but seldom use them anymore simply because they don't kill any better and beats up the gun too much. My background with he 10mm goes waayy back. I was the first competitive IPSC shooter to adopt the 10mm and had a few very modded out limited race guns in the caliber. I have reloaded 10k+ 10mm rounds over the years and have used just about every bullet configuration in the caliber. I was using a 180 grain bullet at 1000fps to qualify for major power factor. This was in 1992. Today guess what bullet configuration the 40s&w top competitors are using????
To recap,....for the average guy that doesn't reload pet loads for the 10mm. The 40S&W will bring to the table what the 10mm was initially designed to do. Especially with today's better bonded bullets, they don't need to be driven that fast to get the job done in and out of the woods. I lived through the heydays of the 10mm craze with the Brenten, Deltas,etc. I had them all as well as a chronograph for IPSC purposes. It's power has become legendary over the years but I can tell you the real world performance specs never were as hot as they said it was commercially back in the day.