Why not an "equalizer" for a 40 cal...with 1000 fps...total weight 200+...it could be done...and would sell well

Why not?

How much energy are we talking about? I'm interested. I would like to hunt with a .40
but in MD I need at least 700ftlbs. I'm not sure that would be safe in a 40.

I can't imagine that you could get that kind of energy out of the 40 - most of the defensive loadings for 40 s&w are in the upper 400 foot lbs range or low 500 foot lbs range.

here are some examples based upon published data on Midway:

Speer 180grain gold dots

Speer 165 grain Gold Dots

Double Taps - 200 grain HP load

the highest I could find in a quick scan

Double Taps 155 grain load

Blue Glaser Rounds

Hornady's 155 grain TAP round

If the highest they can get the rounds to is 560 foot lbs or so - 700 foot lbs is bound to push pressures to unsafe levels.

Guess I'll stick with the 10mm longslide