Playing with the numbers and the sectional density of bullets it would seem that different bullets of the exact same construction with the same or closely similar sectional density should penetrate similarly through the same media.The relationship of the SD ratio of bullet weight to bullet diameter squared(linear association with cross sectional area)ie density, implies this fact.If I am wrong someone please correct me.

If so the the 470--500 gn @ .318 should pentrate similarly to the 500--570gn @.313. Both at 2150fps.The larger frontal area of the 500 should make it a better "stopper" applied exactly similarly.

A exact same construction bullet in 577-750 gr(SD-.313) would appear to have to be driven to 2150 fps to have similar penetration, all other things being equal.This is 8000 fps of energy!!! Yowsers!!The most velocity I have seen on a 750 gr was 2050fps.

Think I will take the 500 NE and be happy with that.Both the 470 and 500 have been shown to have adequate penetration at 2150fps.And the 500 "only" has 5800ftpnds of energy--quite enough recoil-thank you!!