The firearms community loves a good debate — and few rivalries are as enduring as 10mm Auto vs. .40 S&W. Both cartridges share the same parent case and similar dimensions, yet their performance and intended roles couldn’t be more different.
In this deep dive, we’ll explore ballistics, recoil, versatility, and cost, while highlighting Moriarti Arms’ 10mm and .40 S&W AR platforms for shooters who want the best of both worlds.
10mm Auto vs. .40 S&W: The Winner Is…?
The 10mm Auto was introduced in the early 1980s to deliver magnum-level power in an automatic pistol. Developed for the FBI after the 1986 Miami shootout, it offered deep penetration and stopping power — but also strong recoil that many agents found difficult to control.
In 1990, Smith & Wesson and Winchester engineered a shortened version — the .40 Smith & Wesson — that retained much of the 10mm’s energy but fit into 9mm-sized pistols. The .40 S&W quickly became the go-to law enforcement round of the 1990s and 2000s.
Today, both remain relevant — but for different reasons.
10mm Auto vs. .40 S&W: The Winner Is…?
| Cartridge | Bullet Weight | Muzzle Velocity (fps) | Muzzle Energy (ft-lbs) | Effective Range |
|---|---|---|---|---|
| 10mm Auto | 180 gr | 1,250 | 625 | 100–150 yds |
| .40 S&W | 180 gr | 1,000 | 400 | 75–100 yds |
Verdict:
The 10mm Auto clearly outperforms the .40 S&W in velocity and energy, delivering nearly 50% more power. That makes it a superior choice for hunting, defense against large animals, and long-range shooting with AR-platform pistols or carbines.
Visual Chart Tip: Include a ballistic comparison image showing 10mm vs. .40 S&W drop and energy over 100 yards.
10mm Auto vs. .40 S&W: The Winner Is…?
Recoil is where the 10mm’s power becomes a double-edged sword.
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10mm Auto: Snappier and heavier recoil; best managed in full-size frames or AR-style pistols.
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.40 S&W: Softer recoil and faster follow-up shots; ideal for self-defense and tactical training.
If you’re a seasoned shooter or running a Moriarti AR-10MM 16″ M-LOK Upper, the recoil is manageable — and the added power is worth it. But for compact carry or extended range sessions, .40 S&W wins for comfort.
10mm Auto vs. .40 S&W: The Winner Is…?
Both calibers are widely available, but the .40 S&W tends to be cheaper and more abundant due to law enforcement surpluses and mainstream use.
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10mm Auto: ~$0.60–$1.00 per round
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.40 S&W: ~$0.40–$0.60 per round
Reloaders often prefer 10mm for its flexibility in custom loads — from light practice rounds to bear-stopping 200-grain hardcasts.
10mm Auto vs. .40 S&W: The Winner Is…?
This is where 10mm Auto dominates.
For deer, hogs, and even black bear, 10mm delivers penetration and energy on par with .357 Magnum — especially when fired from a longer AR barrel.
Moriarti Arms offers several AR-10MM complete uppers with 16″ barrels, optimizing velocity and accuracy for hunting use.
In contrast, the .40 S&W lacks the energy for ethical medium-game hunting but excels for personal defense and range use.
10mm Auto vs. .40 S&W: The Winner Is…?
The .40 S&W remains one of the most balanced defensive calibers ever designed. It offers:
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Manageable recoil
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Excellent stopping power
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Compact handgun compatibility
Law enforcement agencies have gradually shifted back to 9mm due to modern bullet design, but .40 S&W is still a formidable defensive option — especially for those who already own compatible pistols or carbines.
The 10mm, meanwhile, offers unmatched penetration and power for outdoor defense — a favorite among hikers and hunters who might face predators.
10mm Auto vs. .40 S&W: The Winner Is…?
Both calibers shine in the AR pistol and carbine world, but 10mm has the edge for ballistic efficiency.
With Glock-compatible lowers, both calibers share magazine commonality with your sidearm — a huge plus for tactical efficiency.
10mm Auto vs. .40 S&W: The Winner Is…?
| Barrel Length | 10mm Velocity | .40 S&W Velocity | Accuracy (MOA @ 50 yds) |
|---|---|---|---|
| 4″ Pistol | 1,200 fps | 950 fps | 3.5 MOA |
| 10″ AR Pistol | 1,350 fps | 1,050 fps | 2.5 MOA |
| 16″ Carbine | 1,450 fps | 1,150 fps | 1.5 MOA |
The 10mm gains significantly from longer barrels — up to 250 fps more than .40 S&W in the same platform, translating into flatter trajectories and improved accuracy at range.
10mm Auto vs. .40 S&W: The Winner Is…?
Both calibers are famously reliable when properly chambered. The 10mm operates at higher pressures (37,500 psi) vs. 35,000 psi for .40 S&W, which can increase wear over time.
Moriarti’s AR-10MM upper receivers feature heavy-duty bolts and precision headspacing, ensuring consistent cycling and durability under full-power loads.
10mm Auto vs. .40 S&W: The Winner Is…?
Choose 10mm Auto if you:
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Hunt medium game or want field protection from predators.
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Prefer power and long-range performance.
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Already own a robust full-size pistol or carbine.
Choose .40 S&W if you:
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Want a balance of power, cost, and control.
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Carry for personal defense or concealed use.
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Value quick follow-up shots and lower recoil fatigue.
10mm Auto vs. .40 S&W: The Winner Is…?
In the end, both calibers have their place — but if one has to “win,” the crown goes to 10mm Auto.
It delivers:
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Superior energy
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Greater versatility
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Extended range
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Proven hunting capability
For shooters who prioritize power and performance, 10mm Auto is the undisputed champion.
For those seeking cost efficiency and everyday defense, .40 S&W remains a rock-solid choice.
10mm Auto vs. .40 S&W: The Winner Is…?
Whether you’re running 10mm Auto or .40 S&W, Moriarti Arms builds precision-engineered AR platforms that maximize each caliber’s potential.
With premium components, slick-side uppers, and Glock-compatible lowers, you can build the perfect firearm for your mission — whether that’s range day, defense, or the hunt.
