Not only have I been hunting and killing deer since '70 with handguns but as a LEO in NE Oregon I had the "opportunity" to dispatch a lot of would/injured deer, elk and livestock. I was able to shoot them with what I wanted, where I wanted and then watch them die. Of those I've shot while hunting I've shot a lot with cast bullets of various nose shape and alloys/hardness. I've also shot as many with JSP/JHPs. There is a reason FMJs, even the older blunt nosed ones, were out lawed for hunting big game in every state in this country....simply because they do not kill as efficiently (read that "as quickly") as expanding bullets. That is a fact. Given the same design and velocity a softer cast bullet that expands will also kill quicker, that is a fact also. Hardly any, if any, police departments use a hard cast bullet for duty. Some use soft lead SWCHPs that expand but most use JHP/JSPs because they do more damage and stop the miscreants quicker (read that "kills them quicker" but that's not pokitically correct to say), that is a fact.
I can go on and on with "facts" but it isn't necessary. I'm not saying hard cast bullets are not efficient for hunting, to the contrary they are and I use them myself as stated. The fact that you've not lost a deer and they all died quickly are a testemnet to your hunting skills, your shooting skills and probably where you hunt. However, it is not necessary denegrate soft expanding cast bullet, JSPs or JHPs simply to justify your own choice. It's also rather bad form to get on my case because I proffer a different view, rather biased of you in that regard also. Again, I don't disagree that hardcast bullets are good bullets to hunt with, that they don't work or even that they don't kill well because the answer is "yes" to all the above. I just state that softer exanding bullets will and do kill quicker, that is a fact.
BTW; as you allude to the superior "penetration" (The advantage for hardcast is, I can not only take out the hear lungs, I also take out a front leg any change I get. I take quartering to or away shots to accomplish this.) of hard cast bullets is that a proper soft cast bullet that expands, a JSP that expands or a JHP that expands gives all the penetration required for the same shots. I've yet to recover any of my soft cast HP'd handgun or rifle bullets from any game animal. I've yet to recover a proper JSP/JHP from a game animal from a .357, .41 or .44 magnum....all gave through and through on broadside and quartering shots. One exception being with Texas heart shots, there the hard cast generally does give superior penetration, but then I don't take Texas heart shots so if you do then you've definately the advantage.
Larry Gibson