Are Spicy Pistol Calibers Pointless For Personal Defense? Not at Longer Ranges


10mm Auto (left), .40 S&W (right) (Image: Jeremy S. for TTAG)

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Almost like a memorized prayer, there are certain defensive gun myths that people will recite reflexively. Some of them are correct, some are true with caveats, and others are just garbage with no basis in fact.

One of the big ones that’s mostly correct is that defensive shootings happen in “three rounds, three seconds, three feet” (or some variation of this, like “two rounds, two seconds, two feet”).

This idea has led to a whole industry of guns optimized for concealed carry. Little pocket pistols have been around for a long time, but in recent decades pistols like the Ruger LCP have proliferated. They don’t have much sight radius, barrel length, or magazine capacity, but for that 3-3-3 or 2-2-2 fight, they give you what you need without much bulk and weight.

The industry has rebounded somewhat more recently, with “just right” pistols like the Smith & Wesson M&P Shield, SIG P365, and Springfield Hellcat. Many people loved carrying tiny pistols, but found that they were just awful to shoot, so the industry continues to optimize for more segments of the concealed carry market.

Most CCW guns now tend to be 9mm guns in that “just right” size, increasingly equipped with a red dot sight, for accuracy and speed, especially at extended ranges.

And then came the Greenwood Park Mall shooting, where Eli Dicken shot a would-be mass shooter from 40 yards away with a pistol, and saved dozens of lives. This is far from the first time anyone has taken a long shot like this (I discuss several examples here), but it’s one that woke many people up to the idea that there’s a difference between self-defense and defense in general.

The whole 3-3-3 or 2-2-2 thing is usually true because the person defending themselves is standing at the zero mark and the ability/opportunity/jeopardy framework for reasonable use of deadly force favors smaller distances. But, if you’re defending other people, you have to add the distance between you and the intended victims to the equation. In a place like a mall, supermarket, or most streets, that distance could easily exceed 100 yards, putting the shooter a whole lot farther than 3 yards away.

The YouTube shooting community has responded to this reminder of reality with the “Dickens Drill” (which might not be 100% accurate), with the basic idea of being able to hit targets at 40+ yards with the gun you carry.

While most modern handguns can do this and red dot optics make it far easier, there’s one thing people forget about when taking on the long shots: external ballistics.

Bullet Behavior For These Long Shots

Normally, we can ignore external ballistics with pistols and skip straight to terminal ballistics. Energy losses, bullet drop, and things like windage/elevation just don’t make enough of a difference at 10 yards for most people to need to consider. But, move the target away to 50-100 yards, and we’ve left the world of point blank behind.

It’s generally accepted that more powerful rounds like .357 SIG and 10mm have little to no incapacitation advantage over 9mm when hollow points expand and get good penetration (one ballistics researcher said of .357 SIG, “…what is the point of this cartridge?”), because the extra energy doesn’t cause permanent damage (unless you get to rifle velocities) and therefore doesn’t aid in incapacitation.

But, as the yards fly by, things change.

One problem with most pistol rounds is that hollow points are optimized for the velocity that bullet will have for the first couple of dozen yards. If it goes too slow (and at 50-100 yards, it will), the bullet won’t expand much and will act like an FMJ. This means a lot less wounding and that the bullet will probably zip on through and hit other things, possibly on the other side of the target or through walls (overpenetration).

This is where one of the disadvantages of 10mm and many .357 SIG loads becomes an advantage. Because .40 S&W was made by shortening the 10mm Auto, many manufacturers just put a bullet optimized for the more popular .40 S&W round in there. With .357 SIG, the bullet is the same as 9mm NATO/Parabellum/Luger/Whatever, leading to many manufacturers just putting a 9mm bullet in the .357 SIG case. The result is that, at normal distances, the bullets are going too fast for the bullet design, and tend to expand early and possibly fragment, leading to less penetration in some cases (which is especially weird, given 10mm’s reputation for penetration).

Numbers for .357 SIG 125gr Gold Dot (Blue) and 9mm +P 124gr Gold Dot (Green) defense rounds, out to 100 yards. Screenshot from

But, at 100 yards, when full-power 10mm slows down to .40 S&W speeds and .357 SIG has slowed to 9mm speeds, these bullets will be in their design velocity range and perform ideally. Meanwhile, a 9mm hollowpoint becomes a .380 or weaker round and possibly fails to expand. It’s also important to keep in mind that the faster .357 or 10mm bullets will experience less bullet drop, making it faster and easier to hold over (assuming this is necessary at all for center of mass shots).

Bullet drop for the same .357 and 9mm Gold Dot loads, on a graph. Screenshot from

How I Navigate This Compromise With 10mm

In my reading and research, I’ve found that bonded Speer Gold Dot bullets designed for the slower caliber tend to do well both up close and at distance. For 10mm, the 180 Gold Dot bullet is definitely driven too fast, but the bonded design holds things together and even allows for reasonable penetration, with plenty of damage that occurs during expansion, before it folds back more and becomes a “meteor.”

But, ballistics calculators show that at 100 yards, the .40-caliber Gold Dot bullet would be within normal velocities for .40 S&W, so you’d be able to expect normal closer up .40 Gold Dot behavior at extended pistol ranges. So, it’s still a bit of a trade-off (slightly reduced performance closer up (but still very acceptable), but bonded bullets help expand the useful ranges pistol ammo is useful from.

How Useful Is This, Though?

What I’d really like to see is manufacturers design hollow points that expand at a wider range of velocities. This would be better than the trade-off I’ve negotiated with 10mm, but would require a lot of research and development (assuming it’s possible), and there aren’t enough options like that on the market like that right now.

Obviously, we’re getting pretty far into the long tail of defensive gun use here, and this small tradeoff to get performance at longer ranges might not seem useful to many readers. But, if you’re going to be doing the Dickens Drill and practicing for the long shots, you’d better consider the reduced velocities and potential for non-expansion you can expect at longer ranges as you prepare for that scenario.


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