Reader Anner writes:
Fair warning: what follows is many paragraphs of pure ballistic nerdism. It also follows some assumptions and processes that would probably give my college statistics professor a stroke.
I recently had some time on a business trip to sit and ponder the merits of various calibers, concealed carry platforms, and the wealth of data we enjoy these days. Folks such as ShootingTheBull410 and LuckyGunner Labs have done us an incredible service in applying terminal ballistics research to the types of handguns and barrel lengths we routinely carry.
I’ve had a long love affair with the idea of carrying a .357 Magnum revolver. A smooth DA trigger, a legendary cartridge, and the pride of training to employ a classic (if possibly outdated) design…it turned into an emotional drive.
I tried several makes, models, and barrel lengths: J-Frames, K-Frames, a Rhino, SP101s, an LCR, and even a Ruger Vaquero. The footprint and weight of the smaller models compared favorably with a subcompact or single-stack pistol, but were torturous to shoot with the ammunition I wanted to use. Larger and heavier models were more comfortable to shoot, but a brick on the belt.
I had a Ruger LCRx, 3” barrel, .357 Magnum and a set of XS sights in the online shopping cart of my local FFL, ready to purchase. When I returned home to pick it up, it would be my final attempt to find the perfect balance of weight, footprint, handling, and shoot-ability.
However, I needed to research if those fiver rounds really had the terminal effectiveness to justify replacing a pistol with seven to ten rounds of capacity.
While I didn’t use any data from his study, Greg Ellifritz provides an excellent background on what I call “second-order” data. It’s a study on how humans reacted to instances of being shot, with all of the variables we can’t replicate in ballistics gelatin: psychological stops, sober or drugged assailants, etc. It’s worth a watch.
LuckyGunner Labs has some ammo on their hands, and performed a standardized test of common self-defense calibers into Clear Ballistics gelatin. I applaud Chris Baker and his co-workers on their extensive testing and impeccable presentation. You can see their work here.
DATA COMP – ROUND 1
The purpose of this data comparison is to compare the terminal ballistics of various calibers fired through concealable handguns. Two exceptions are the 10mm and .357 SIG tests, which used full-size handguns. To standardize the data as much as possible, not all loads LuckyGunner tested are displayed.
Displayed loads had to meet the following criteria:
1. At least 4/5 rounds fired in the provided barrel length expanded, demonstrating proper terminal function in a self defense role. A round was NOT excluded if it failed to meet the 150% expansion diameter desired; if it appeared to expand to (or close to) its design limits, it is included, and the audience can conclude if that’s ‘enough’ expansion.
2. Loads penetrating outside the 12-18” ideal range (generally due to over/under-expanding) are shown. By focusing on proper bullet function (expansion) instead of penetration, the audience can determine if they’re comfortable carrying a load that expanded beautifully but under- or over-penetrated.
3. Generally, does the load satisfy the requirements of something I would carry? Not that I would actually carry it due to other factors, such as availability or reputation of a specific manufacturer, but does the performance observed generally demonstrate good self defense load characteristics?
4. By eliminating loads that did not perform as designed, we can focus on how effective each caliber is when loaded with a specific bullet design and pushed to a velocity typical of shorter barrels.
The intent is to draw conclusions on the terminal effectiveness of the caliber by assuming proper terminal function/expansion, and then comparing the degree of expansion and penetration…yes, it’s a caliber wars session. Sharpen your spears. Once a specific caliber shows the desired performance, I can choose a carry platform and select from individual test data for the best carry load.
TABLE NOTES:
1: S&W M&P Compact, 3.5” barrel
2: Kimber K6s, 2” barrel
3: Ruger GP100, 4” barrel
4: GLOCK 27, 3.42” barrel
5. Kahr CW45, 3.64” barrel
6: GLOCK 42, 3.25” barrel
7: GLOCK 20, 4.6” barrel
8: GLOCK 31, 4.49” barrel
LOADS MET CRITERIA is the number of loads that met the above criteria; LG TESTED is the number of loads LuckyGunner Labs tested, representing an illustration of the commercial availability of self-defense loads in that caliber.
A high percentage of tested loads meeting my criteria does not rule it out as an effective carry caliber; it does mean I’ll be picky about which load I carry.
Units: Weight (Wt) in grains, muzzle velocity (MV) in ft/sec, muzzle energy (ME) in ft-lbs, Penetration in inches of Clear Ballistics Gel after 4LD (4-layer denim), Expansion in inches, Volume in square inches as a product of the ‘cylinder’ of penetration and expansion.
All numbers are averages of a total of five (5) rounds fired into the same gel block.
“+P” designations only applies to the calibers specifically noted (9mm, .45 ACP, .38 Special); other calibers in that row are standard pressure. Loads offered in original designs and bonded designs are designated as such. SB = Short Barrel, T&D = Train and Defend, SJHP = Semi Jacketed Hollow Point, GD = Gold Dot, VC = V-Crown, LSW = Lead Semi Wadcutter, Rem = Remington, Win = Winchester
DATA COMP – ROUND 2
Are your eyes bleeding yet? Here’s a summary of the above data.
PENETRATION AND EXPANSION
1. .380 ACP is a weak and consistent under-penetrator, requiring careful carry ammo selection. Solid bullet designs, such as ARX and Lehigh may be the best option if you must carry a .380. These will ensure adequate penetration and still deliver a respectable wound track via mechanisms unique to their “Phillips-head” design. ARX Inceptor is significantly cheaper than Lehigh designs, and generally available in local gun stores. See ShootingTheBull410 videos for more information; his results contradict some results seen here, specifically the performance of Hornady Critical Defense and XTP.
2. .38 Special was a surprising under-performer. When it did expand, it barely met the minimum penetration. Carefully choose your carry ammo, and carefully evaluate that little 5-shot snubbie as your primary carry option. Every decision in this arena is about risk mitigation; in your everyday life, a 5-shot snubbie may be more than you ever need.
3. Look at the performance of 9mm vs. both barrel lengths of .357 Mag…what?! Practically identical penetration and expansion, despite the .357 Mag’s 60-180 ft-lbs more energy at the muzzle! Now, we are talking averages across a wide variety of bullet designs and powder types/charges. However, think of the mystique surrounding the .357 Mag, particularly with Remington (or Federal, though that’s not represented in Lucky Gunner’s data) 125gr SJHPs. They’re impressive, of course, but averaging out a spread of .357 Mag self defense loads essentially produces 9mm terminal performance. Now, consider that the 9mm test barrel was 3.5” while the revolver test barrels of 2” and 4” don’t account for the 1.6”+ chamber length. A 4” barreled .357 Mag will possess an OAL significantly longer than a subcompact 9mm pistol, and generally produce identical terminal performance.
1. Does .357 Mag still destroy 9mm? Absolutely it does…in longer barrel lengths. .357 Mag is a high pressure round with lots of powder to burn. Comparing data from Ballistics By The Inch, .357 Mag screams out of longer barrels and continues to gain velocity as far out as 18” barrels. 9mm is efficient in handgun-length barrels, and plateaus around the 12-14” barrel mark. A 16” barreled .357 Mag carbine will humanely take deer out to 150 yards, while a 9mm AR carbine is best-suited for plinking or home defense at more modest ranges. Each caliber functions most efficiently in different barrel lengths. In a concealed carry discussion, 9mm performs just as well as .357 Mag.
2. What are the practical effects of pushing a .357 Mag out of a 2-4” barrel? Muzzle blast, limited capacity, and recoil. The extra expanding gasses and un-burned powder that escape out of the muzzle never helped accelerate the bullet, and are still shooting forward at extremely high velocities. If the gun is stationary at time = ignition, the combined momentum of the bullet, gasses, unburned powder, etc. are all conserved as an opposite motion of the revolver, slamming into your wrist. A cartridge that burns every bit of powder and has a small pressure differential at the muzzle will produce little additional recoil over a factor of the bullet’s weight and velocity. This is the major difference between .357 Mag and 9mm handguns in terms of muzzle blast and recoil. Other factors, such as the slide of a semi-automatic pistol retracting or a polymer frame flexing, decrease the impulse (change in momentum over time…time is increased so maximum force is decreased to deliver the same overall momentum).
3. This project started with a desire to prove that the power and terminal performance of .357 Mag justified its capacity handicap. I truly want to carry a revolver for self defense…but I can’t ignore all the drawbacks of .357 Magnum at zero increased benefit vs. 9mm.
4. Out of a 4.49” barrel, .357 SIG produced higher muzzle energy than .357 Mag out of a 5.6” barrel (4” barrel + ~1.6” cylinder). .357 SIG demonstrates nearly identical expansion as hotter .357 Mag or 9mm loads, but uses that extra energy in driving the bullet deeper into the gel. Given the cost and availability of ammo and decreased capacity, I see no practical benefit over 9mm offerings. If you need the impressive penetration of .357 SIG, consider buying 9mm ammo that will deliver the same effect, such as copper/fluted slugs from Lehigh. You can have the same terminal effect without a dedicated .357 SIG platform. You can also use a .357 Mag with a longer barrel to bump muzzle energy, though at the cost of decreased capacity and less concealability.
5. 10mm is poorly represented in the final results, a factor of weak factory loads. If you carry a 10mm for self defense against human attackers, consider that you’re accepting more recoil, costlier ammo, and a handgun that’s harder to conceal for little terminal gain. However, 10mm excels with the right ammo in specific applications. Actual 10mm spec loads from Underwood or Buffalo Bore provide excellent 4-legged game loads, for defense or offense, in situations more prone to open and comfortable carry. Lehigh solid copper bullets loaded by Underwood punch through vehicle bodies and other barriers with ease, potentially providing armed security or gate guards a lightweight option to backup their rifles. Outdoorsman can have a 15+1 pistol with 200gr hard cast loads for black bear or mountain lion defense.
6. Here’s the fun part. On paper, .40 S&W is a self defense champion, a spectacular mix of penetration, expansion, and magazine capacity. Significantly better performance than 9mm, just shy of .45 ACP performance, and boasting higher capacity in firearms closer in size to 9mm than .45 ACP. But you knew all that, didn’t you? So why is .40 S&W no longer the law enforcement darling it was just a decade ago? I’ve owned several, shot them side-by-side with every other caliber in this comparison, and ended up selling all of them. Several models of 9mm and .40 S&W pistols are identical in size, providing a perfect comparison. The G26 was a pussycat, the G27 was a snappy beast. The XD-S in 9mm was a little snappy, but manageable by even smaller shooters; the XD-S in .40 S&W removed layers of skin (the grip texture is aggressive). The Kahr P-40 hurt, the CW-9 didn’t. With every .40 S&W model I carried, I found my first-shot accuracy on steel, split times, and general performance suffered. 9mm offers a more pleasant experience, and more confidence that I can quickly and accurately place rounds on a bad guy. With solid performance from several modern 9mm defensive loads, I don’t see the benefit in sacrificing a little capacity or shooting comfort for a .12” wider bullet in gel.
7. .45 ACP…along similar lines as the 9mm vs. .40 S&W discussion, .45 ACP in small handguns has rarely been as brutal as .40 S&W. It can be stout, especially in the slim and aggressively-textured XD-S, but the impulse is slower and felt recoil is smoother…almost like a shove rather than the .40’s piercing jab. .45 ACP threw up some impressive averages, with the widest expansion and penetration right in the middle of an ideal 12-18”. In terms of FBI terminal ballistics, it’s the runaway champ. Individuals will need to consider limited capacity and felt recoil vs. less powerful calibers, and how that translates into making effective hits on a bad guy in a timely manner. However, with a quality .45 ACP self defense round, I sincerely doubt any failure to stop a bad guy can be blamed on the choice of caliber.
DISPLACED VOLUME
The FBI’s “Handgun Wounding Factors and Effectiveness” report noted that handgun rounds generally do not have the energy to create the same type of trauma as rifle rounds. Skin, organs, and internal tissue are extremely resilient and difficult to actually tear or destroy. If you’ve ever field-dressed medium game, you know how tough heart, lung, and muscle tissue can be.
According to the FBI, we can only rely on the narrow channel of damage that an expanded handgun bullet produces; meaning, a round placed into the left lung of a bad guy isn’t going to create a violent over-pressure and collapse his right lung. With a rifle firing an effective load for a given situation, we may see trauma extend well past the bullet’s narrow path.
Therefore, I calculated the total displace volume of each round, approximating that volume with a cylinder. The height of the cylinder is the penetration, while the radius is half of the expanded diameter. This does not take into account the displaced volume before the round is fully expanded; in those first couple inches of gel, before a hollow point functions and expands, a .45 ACP will be displacing roughly a half-inch wide hole.
Reviewing slow-motion function of many hollow point bullets in gel, most quality designs are fully expanded after 3-4”. From that point on, the average .45 ACP is tearing a 0.73” wide hole. However, we’re just calculating numbers here to compare terminal performance among handgun calibers, not to set any testing standard for what displaced volume bullet designers should strive to meet. Therefore, simplifying the calculation for all calibers keeps the data comp even.
All included data averaged out to 4.6in2. The three classic semi-automatic carry loads (9mm, .40 S&W, and .45 ACP) averaged 5.6in2. .45ACP ruled the roost here, with an impressive 2.5x the displaced volume of .380 ACP. 9mm and .357 Mag (out of both 2” and 4” barrels) were identical. What does this mean? At the risk of confirmation bias, it appears .45 ACP does a lot of damage. Science.
FINAL THOUGHTS
I’m sincerely saddened by the results of .357 Magnum out of short barrel lengths. I badly wanted to justify carrying a Ruger LCRx with a 3” barrel, boasting the muzzle energy of a freight train and the terminal effectiveness of a Ma Deuce. Alas, my Walther PPS M2 with 147gr HSTs is just as likely to stop a threat, all without the muzzle blast, recoil, and limited capacity of the LCR. My wife and my credit card are both content with that result.
I’ll admit to packing a .380 ACP when it seems appropriate. I’m now more motivated to stick with a ‘real’ caliber whenever possible.
I’ve tried .40 S&W in several platforms, and since wandered away. I value performance out of tiny carry guns in a pragmatic sense, but when other calibers deliver nearly the same or more performance and allow me to place good shots faster, I can’t justify the trade-off. This data gives a hearty endorsement to .40 S&W starting when the bullet meets gelatin, but not enough to pull me back in that direction.
I’m still torn on .45 ACP. My XD-S is an excellent carry platform, one of my favorites. It allows me to throw on a weapon light for nightstand duty, doubling up purposes while on road trips or camping. Even with a 7-round extended magazine, I don’t know if better terminal performance balances out the significant drop in capacity vs. a similarly-sized 9mm.
EPILOGUE
I ran some additional comparisons on 23 potential concealed carry platforms, some I own and some I do not. I compared width, length, height, barrel length, caliber (using average displaced volume as a metric), capacity, etc. Each metric had a score; for example, heavier weight or lower capacity handguns received penalties.
The P365 won by a slim margin, but I won’t carry it for obvious reasons. The XD-S in both 3.3” and 4” barrels tied for second place, and likely my ‘forever’ carry gun combo. The Rex Zero 1 and GLOCK 20 were right behind the XD-S family. The loser by a wide margin was the Ruger Vaquero…poor fella, it’s nothing personal.
If you stuck with me all the way to the end, I appreciate your patience.