.40 S&W vs .45 ACP: It's Time to Settle the Big-Bore Auto Debate

Ever since the 40 S&W cartridge hit the market, shooters have been debating which is better, the 40 vs 45 ACP. It makes sense because both cartridges basically do the same thing. Let’s break down the pros and cons of .40 S&W vs .45 ACP.

40 vs 45: Does it Even Matter?

Let’s get this part done first: no it doesn’t. Handgun stopping power is a myth. With modern, well-made defensive ammo, .40 vs .45 is kind of a pointless debate. Look at the data on Speer Gold Dot, for example. There’s a 180 grain Gold Dot for the 40 S&W and a 185 grain Gold Dot for the 45 ACP. In independent ballistic tests, both meet the FBI minimum penetration standards, and both expand to over 0.60 inches. And that’s after defeating 4 layer denim.

The results don’t really change if you change bullet weight either. A 230 grain Federal HST in 45 expands a bit more than a 155 grain HST in 40, but that’s it. Interestingly, despite the 45 ACP having a larger bullet diameter than the 40 S&W, in the case of 230 grain vs 155 gr HST, the expanded diameter difference is smaller than 0.05.

To put the bottom line up front, there is no debate. Pick whichever you like best and vaya con dios, amigo. But then this article wouldn’t be very long, so let’s get into it.

You Should Pick the 40 S&W Because It Holds More Rounds

The biggest argument in favor of the slightly smaller round in the 40 vs 45 debate is that 40 S&W holds more rounds in pistols of similar size. For example, a single stack 1911 holds 8 rounds of 45 ACP but can hold up to 10 rounds of 40 in a magazine that’s still concealable. If we’re keeping score in 40 S&W vs 45 ACP, that one is a clear win for the shorty 40. More ammo is always better, right?

You Should Pick the 45 ACP Because it’s Nicer to Shoot

40 vs 45 ACP, this Colt only holds 8 rounds — This was the author’s personal carry gun for a year

I have shot a ton of both rounds. Over a 3-year period, I shot 13,000+ rounds of 45 ACP through a bunch of different semi-auto platforms, most of which was a Glock 21. Over the same period, I shot about 7,000 rounds of 40 S&W, almost all of which were through Glocks. I can say with absolute certainty that I enjoyed shooting the 45 ACP a lot more. Most shooters agree as well, that the recoil impulse on 45 ACP is more pleasant despite it being a larger caliber, especially in polymer-framed pistols than the recoil impulse on the 40 S&W.

40 vs 45 Is a Silly Debate and You Should Get a 9mm Pistol

Of course, if the only difference in 40 S&W vs 45 ACP is that 45 is nicer to shoot and 40 holds more rounds, the real answer is to get a 9mm. It’s nicer to shoot than both calibers AND it holds more rounds than either. But if you’re really committed to this discussion, we’ll make a recommendation.

Editor’s Choice: 40 S&W

This one makes sense, at least to me. First, you do get more rounds with 40 S&W. Secondly, with careful ammo choices, such as Federal’s 205-grain Syntech Action Pistol round, 40 is just as nice to shoot as 45 ACP. Lastly, thanks to law enforcement agencies in America switching to 9mm, there are loads of affordable, high-quality 40 S&W semi-autos floating around the secondary market right now. A police trade-in Gen 3 Glock 22 is a great gun, and with some of the current prices it just makes sense. With caveats, if the question is 40 vs 45, then I’m going 40 S&W.