Basically, we were told that the rounds would break up and more or less explode inside every time one entered the body. These lessons about the temporary cavity and its disruptive and destructive force was used as justification for the "Hammer Pair" where two shots were fired as fast as possible. The theory, according to our instructors was that while the temporary cavity of the first shot reached its maximum size, the next shot would be so close and HAMMER the area with the combined temporary cavities. This, in their words, would devastate and destroy the tissue without a doubt. Looking back on it, it sounded good on paper if the target was standing still and if the ammo actually performed as advertised.
Now let me fast forward to when I started shooting as a civilian. I fell into the same trusting state that I was in during Boot Camp where I just took what I was told and ran with it. But, just like the LESSONS I was taught about ballistics in Boot Camp, the reality of the .45 ballistics was quite different from what I was told or what I just thought. It took little research to find out that the "puny" 9mm actually had more power and pressure than the .45 ACP. The .45 ACP had more kinetic energy, but was slow and if it was too slow, the hollow point would fail to open, leaving you with an unknown on whether it is going to go all the way through or not. I did alot of tests and concluded that the .45 ACP was best utilized in barrels 4.25" or longer. This seemed to deliver the best reliable performance with the 230 grain hollow points across the board.
After I did more research into the other calibers out there, I started tinkering with the .40 cal. I found the cartridge to be more snappy and to be more intriguing than the .45 ACP. What I found in the .40 was that most of the hollow points were very reliable at expanding in shorter barrels, but the 165 grain varieties seemed to be the best performers in penetration and expansion.
I really like the .40, even to this day. I like the reliable terminal performance and barrier penetration it offers. For me, I really wish I could find a .40 that would bring me back over. The only issue is the price involved, even with reloading. If ammo became less expensive, I would gladly switch over to .40 again and reload it even. Until then, I will have to decline due to the fact that .40 costs as much as .45 ACP here in Alaska.
After toying with the .40 S&W, I started thinking more about capacity and got pulled into the capacity argument that stated that capacity ruled over performance. Well, in some cases that is true, but it is far from a rule. In barrier penetration, the 9mm still has alot of work to do in order to catch up with the .40 S&W.
The one advantage 9mm has over the .40 S&W and any other caliber is price. I can reload the 9mm for about $0.10/round or less. This makes it incredibly easy to practice on the cheap. With the low recoil, the high capacity potential, and the low price, I was hooked. Today, I am happy to have 9mm pistols, but there is something about the 9mm that just doesn't satisfy the shooter inside me.
Now that I am into reloading the 9mm, I have seen that I can also get into other calibers for less. This has led me to feel that perhaps the 9mm is not the caliber for me. Perhaps now I can invest in .40 S&W and make it my regular carry caliber. I just feel that the performance terminally and through barriers has shown the incredible advantage you get. Perhaps I will take a more serious look at the .40 S&W in the future. For now, I will stick with the 9mm and deal with my dissatisfaction for the time being.