Some people worship at the altar of the .45 ACP, as it is the biggest pistol bullet. “I would carry a .46 except they don’t make one. The .45 doesn’t just stop the bad guy; it kills his soul…” and the list of trite sayings goes on and on. Other people proudly proclaim their heresy and pack 15-20 rounds of Euro pellets in their plastic fantastic. “The Army switched from the .45 to the 9mm, so it must be great. The only time you have too many bullets is if you are swimming or on fire. I can miss 2/3 of the time and still get as many hits as your 1911…”
Let’s just say, I am not a fan boy in either camp. There are great options in both categories and the gun you should carry—bet your life on—is the one you know and trust. The one with which you have mastered the manual of arms and are competent to hit with—frequently and fast. It should also be a gun you can/will carry with you all of the time; and I don’t mean in your glove box. That little caveat puts more pocket .38 specials and .380 ACP’s into action than any other part of choosing a carry gun.
The .45 ACP (.451) is bigger and provides a larger entry hole than a 9mm (.355). However, upon expansion, modern jacketed hollow points from tier-one bullet makers don’t show a huge difference. The 230-grain .45 penetrates based on bullet weight more than velocity. The lack of velocity often restricts the amount of expansion and some JHP bullets barely expand while others open phenomenally. A thorough study that I was once privy to compared over 20 choices. There were many in the non-expansion category, a slightly larger group in the .55- to.70-inch range and two just breaking .80 inch—Federal 230-grain HST and Federal Tactical bonded +P. One overachiever hit a full one-inch of expansion (Winchester 230-grain Ranger T series). All three named bullets averaged roughly 14.5 inches of penetration.
A note on the 200-grain bullets, tread carefully here. Of the bullets tested, more than 60% had little or no expansion and none were close to the top performers. Failure to expand was much less prevalent with the 230-grain options.
The 9mm bullet penetrates based on a narrower cross section and high velocity. The momentum slows much more quickly than the .45, but a well-made bullet does so by trading speed for expansion. In the same study, there were also many bullets in the non-expanding category. Those that did expand broke into three groups. The first group was small in number as well as expansion, ranging from .36–.40 inch. The next group far exceeded that group in both count and expansion. They ranged from .46–.66 inch. The overachievers in 9mm hit .68-74 inch. As 9mm has many options with bullet weight and pressure options, the results need more break down.
The 124-grain choices maxed out at .66 inch—Federal HST +P and Remington Golden Saber +P. The Federal HST in standard pressure was not far behind at .61 inch. All three exceeded 17 inches of penetration.
The 147-grain an up range had two stellar performers. The Federal 150-grain Micro HST expanded to .71 inch, and the Winchester 147-grain Ranger T-series opened to .74 inch. Both exceeded 16.5 inches of penetration.
The test result that shocked me was the Barnes 115-grain TAC-XPD +P with a .70-inch diameter and 13.4 inches of penetration.
The 230-grain .45 ACP tends to be much better at breaking bones and crushing through barriers. The lower velocity and higher weight tend to resist deflection when hard objects are encountered. In contrast, the 9mm (especially lighter choices) is more likely to deflect. Inside the body, this can create an additional wound channel; but against a car windshield, there is a much larger chance of the bullet deflecting harmlessly away.
My article chose to focus on the amazing performers. Be aware, there are complete non performers that wear ‘big name’ brands. Most are older designs or geared toward shooters who think one aspect is the only thing that matters. There are also a couple of choices where the bullet design is a complete gimmick, as evidenced by testing. One brand in .45 ACP didn’t expand at all and penetration failed to break 11 inches. In 9mm it achieved .02 inch of expansion and failed to penetrate to 10 inches. In my opinion, neither of these options provides anything resembling marginal performance. Some FMJ bullets perform better than that, with some slight expansion and at least hitting the FBI’s minimum penetration of 12 inches.
In summation, many of the modern, name brand bullets in both .45 ACP and 9mm will do the job well. This data should help you realize, with the proper bullets, ammunition effectiveness is not nearly as large a concern as it once was. The best .45 ACP provides 1.00 inch of direct wound path and 14.5 inches of penetration in ballistic gel. Most carry guns chambered in this caliber have less than 6 rounds on board. The best 9mm provides .74 inch of direct wound path and 16.5 inches of penetration in ballistic gel. Most carry guns in this caliber have less than 8 rounds on board. In both calibers, full-sized guns often carry significantly more—up to 15 and 21 rounds respectively. In my opinion, this means ergonomics, size versus concealability, price, and personal ego or mindset are the real deciding factors.
You should of course do your own testing on ballistics gel, or as I do with a pork butt. Make sure to run at least 50 rounds through your gun for function testing (more is better). Carry the gun and caliber that works for you.
For honest disclosure, the gun on my hip as I write this is a Smith & Wesson M&P 9mm (plastic fantastic) in 9mm. She holds 18 Speer Gold Dot standard pressure bullets, .54 inch on expansion and 18.1 inches of penetration. As a result of this research, I will be testing the Winchester 147-grain Ranger T- series, 150-grain Federal Micro HST, and Barnes 115-grain TAC-XPD +P for reliability and accuracy in my carry gun.