This'll be my only post on this dead horse
Though Energy in Ft Lbs may be near equal
the Momentum is not equal at all with the
O.P>'s example: and of course trajectory
differs - 9x19 & .40 S&W are flatter shooting than .45 ACP
Taylor KO Calculator *
------------------- Ft Lbs --- Momen. --- Taylor KO
- 9mm Luger ------- 364 ----- 20 -------> 7
--124 gr. GDJHP
-- @ 1,150 FPS**
-- .45 ACP ----------- 404 ---- 29 -------> 13
-- 230 gr. GDJHP
-- @ 890 FPS**
and let's throw in
-- .40 S&W ---------- 419 ---- 26 --------> 10
-- 180 gr. GDJHP
-- @ 1,025 FPS
John Taylor's KO Factor relates his observations
and gives greater weight to Bore/bullet Weight
* Taylor KO Calculator at:
http://www.n4lcd.com/calc/
** from SPeer Ballistic Tables
AND it's not calibers, it's cartridge's
perfformance
Now, I'll go get a beverage and popcorn
Randall