While I agree that observation of the effect of each bullet type strike in sand or dirt, either wet or dry, is not really definitive. What does make a difference in terminal performance in any medium is meplat diameter. This is why handgun bullets intended for hunting have large meplats.

While many suppose that the shoulder of a SWC type bullet will cause full diameter cutting in soft tissue this is simply not correct. Tissue is deflected by the meplat causing a larger cavity than the full diameter of the shoulder, which doesn't touch tissue until the bullet speed drops near zero. The shoulder of the SWC is intended to cut clean full diameter holes in paper targets, just like a full WC, nothing more.

The SWC has a better coefficient of form, ballistic coefficient, and form stability than a full WC. This results in better accuracy at distances where the full WC would begin to degrade and even begin to tumble. This is generally accepted as being anything over 50 yards.

chipking,

The short answer is yes, the larger meplat diameter is what makes the difference.