Bullet shape has a dramatic effect on the wounding potential of non-expanding bullets in soft tissue, so not all FMJs are created equally. Truncated cones are superior to round nose bullets, and WFNs are superior to TCs. The 325 gr hard cast WFNs I load in my .44 magnum do not upset at 1200 fps, but in soft tissue their performance is impressive, and they penetrate deeply, even when bone is hit. When bone is penetrated, a FMJ looses less velocity than a hollow point of similar weight and velocity, that has upset prior to hitting the bone. A long non-expanding tapered bullet, more typical of rifle than handgun bullets, is more prone to erratic penetration due to it's tendency to swap ends or follow the path of least resistance, whereas a short non-expanding bullet with parallel sides and a flat or hemispherical nose tends to penetrate in a straight line. These are all important considerations if you are defending yourself against four footed threats which tend to approach you head first.
If you need to defend yourself from a lethal bipedal threat, face on center of mass shooting is likely the answer to the problem. The hollow point pistol bullet is the gold standard, first due to the benefit of massive for caliber soft tissue wounding, where bigger is indeed better, and secondly due to the "perceived" reduced downrange danger from through and through penetration. A FMJ, particularly a truncated cone or a WFN might arguably be a better performer if your shot was to the point of the shoulder or side on through the pelvis, but no one sustaining those kinds of hits from 9mm/.357/.40/.45 hollow points will be in any position to continue hostilities, so the difference in performance in those circumstances doesn't justify the choosing a bullet design that would prove less effective in a face on confrontation.
