A Complete Guide to 10mm vs .40 S&W

Factors That Influence Bullet Performance

A bullet’s performance stems from goals and expectations that you, the shooter, need. Those may include:

• 1 Shot Drop
• Long-distance accuracy
• Multi-shot accuracy
• User Control

These are some of the tools we use to measure whether a bullet is a good fit for our needs and how we sum up how it performs. Some of the factors that influence bullet performance are incurred due to the bullet’s design and some are purely user errors. You have control over only part of that group – user error and the other attributes are due to bullet design. Those factors include:

• Velocity
• Gravity or bullet drop
• Trajectory – including mid-range trajectory and maximum ordinate
• Line of Departure and shot angle
• Environmental conditions, such as wind

1.Velocity or bullet speed is a common stat that lists the rate the bullet travels in feet per second. How fast the bullet moves from the gun to the target is important as it impacts the trajectory and accuracy of the round.

2.Bullet Drop or the degree to which gravity pushed the bullet towards the earth. The effect of gravity is measured at 32.17 feet per second. If we are talking trajectory, then bullet drop is the point in time from firing to when the bullet hits the ground. It is the pressing down of the round as it flies and is what causes the backend arc of a bullet’s trajectory.

3.The trajectory is the bullet’s flight path as it leaves the muzzle until it stops. Generally, these are arcs. The trajectory is impacted by gravity which induces bullet drop. That is why guns are aimed slightly upwards when fired. If you point the barrel at a distance target and you aim directly, the round will leave the muzzle and gravity will for it down. If you are target practicing and your shots are low, elevate the barrel slightly to compensate for bullet drop. By doing so, you are increasing the angle of the bullet’s trajectory and countering the impact of gravity on the round.

4.The mid-range trajectory is difficult to measure in the field. It is the middle point between the gun and the target or the gun and the point where the bullet strikes the earth. If your target is 400 yards away, the mid-range trajectory would occur at 200 yards. That is, you would measure the mid-range trajectory at its height at the 200-yard mark. Because bullets travel in an arc, and each half of the arc is generally equal, you would use the mid-range trajectory to measure where the shot will hit.

5.Maximum Ordinate is the maximum height of the trajectory. It is a measurement of two angles. The first is the arc of the trajectory, and the second is the straight-line distance from the line of sight. The line of sight is flat. Maximum Ordinate is the point where the arc of the bullet meets the line of sightline. While technical, maximum ordinate helps you determine what happens at the point-blank range.

There is a good reason why many rounds come in a variety of formats. While some of that is due to use in different guns, much of it is to correct performance under certain firing conditions. These include attributes such as casing material, whether the bullet is an FMJ or not, and specialty tips such as hollow tip vs. rounded tip vs. poly tip.

Of course, there are factors such as grain size too which will ultimately determine factors such as velocity and energy.

10mm vs .40 S&W: A Breakdown

SIZE

10mm – Overall length – 1.2 inches

.40 S&W – Overall length – 1.135 inches

WEIGHT (GRAIN)

10mm – Offered in a wide range of grain sizes including, 77, 155, 175, and 180 grains.

.40 S&W – Offered in a wide range of grain sizes including 115, 135, 155, 165, and 200 grains.

PERFORMANCE

10MM

77 = 649 lb-lbf
155 = 775 lb-lbf
175 = 649 lb-lbf
180 = 708 lb-lbf

.40 S&W

115 = 500 lb-lbf
135 = 588 lb-lbf
155 = 463 lb-lbf
165 = 468 lb-lbf
200 = 490 lb-lbf

VELOCITY

10MM

77 = 2,420 feet per second
155 = 1,500 feet per second
175 = 1,290 feet per second
180 = 1,300 feet per second

.40 S&W

115 = 1,400 feet per second
135 = 1,400 feet per second
155 = 1,160 feet per second
165 = 1,130 feet per second
200 = 1,050 feet per second

Uses

10mm guns are okay for home and self-defense. They come with a much larger recoil than the .40 S&W making them difficult to use in rapid shot succession. Also, the recoil from the 10mm can intimidate shooters with weaker arm and hand strength. The power of the 10mm will stop predatory animals and it is relatively easy to holster and carry. It is impressive for the gun range too.

The .40 S&W is a good option for home defense and self-defense situations. The slightly weaker rounds help prevent accidental injury due to the bullets penetrating walls. It has enough power to stop an intruder and offers a lighter recoil that makes it a nicer, friendly gun for those of us with weaker arm and hand strength. It is slightly smaller so easier to conceal carry. A very appropriate round/gun for the range.

.40 S&W 155 gr Hollow Base Flat Point – 1000 rounds – Expect to pay about $165 or for 250 rounds for about $47.

10mm 180gr Flat Point Thick Plate – 1000 rounds – Expect to pay about $180 or for 250 rounds for about $55