You do need to have enough frontal area driven at enough speed. The flat might not be earth shattering in gel versus the RN, but anyone who's ever killed anything generally skip the RN.
Flat nosed 45s seem to "whomp" armadillos harder than round nosed. Not scientific I admit.
It needs to be duplicated in a lab, preferably by a company that sells bullets in order to be quantified properly.
Ignore the facts that as far back as WWI, militaries banned the truncated cone and Colt New Police cartridges generally differed from S&W counterparts in one regard: bullet nose profile.
If they only had ballistics gel....
