Of all the small-bore cartridges the 5.7x28mm appears to be the best of the bunch. It’s quite accurate, allows a high magazine capacity in a handgun, has mild recoil and is capable of penetrating a substantial amount of soft body armor. It also appears to offer an edge in terminal performance over its small-bore peers.

However, many qualified individuals still question if the terminal performance of this round is adequate for military use. What becomes of the 5.7x28mm, if anything, regarding widespread military adoption remains to be seen.

Strengths: excellent penetration of soft body armor, very good accuracy, mild recoil, high magazine capacity, a variety of loads available, growing more common, produced by a recognized leader in the small arms industry.

Weaknesses: bright muzzle flash, untested terminal performance in military use.

5.8x21mm
One little-known recent development is the 5.8x21mm cartridge recently fielded by China. For decades, the standard service pistol of the People’s Liberation Army has been the 7.62x25mm Type 54. When the PLA began looking for a suitable replacement for the Type 54, it decided to replace the 7.62x25mm cartridge with a small-bore, high-velocity round. Chinese engineers believed such a projectile would yaw quickly in tissue and produce a larger wound cavity than a conventional 9mm FMJ projectile. In this way they hoped to enhance terminal performance.

By pushing the small, 5.8mm projectile to above-average velocities, penetration of body armor would also be substantially improved. It was envisioned the new cartridge would be able to outperform any 9x19mm armor-piercing loads in this regard. Recoil would be light, allowing fast follow-up shots. Plus, as the cartridges would be smaller and lighter, magazine capacity would be greater, allowing more rounds to be carried.

The end result of is the 5.8x21mm DAP-92. It’s a small bottlenecked cartridge with an overall length of 33.5mm. The copper-washed steel case is 8mm in diameter at the rim and has a slight taper to aid reliability. Overall cartridge weight is just 92.5 grains.

The cartridge is topped with a .236-inch armor-piercing projectile weighing 45 grains. The projectile features a steel jacket, a hardened steel penetrator and a lead filler in the base. The PLA claims a muzzle velocity of 1,574 fps when fired from its newly adopted QSZ-92 service pistol.

The PLA says this round will penetrate a 1.3mm-thick plate of 232 helmet steel and two inches of wood planking at 50 meters. During testing performed by the PLA in 12-inch blocks of soap, the load yawed within 1 centimeter of entry and tumbled--leaving a cavity 2.5 times larger than a 9x19mm FMJ. Recoil, as to be expected, is mild. Accuracy is said to be good, with a 20-round group having an extreme spread of 2.1 inches at 25 meters.

The Chinese went on to adopt QSZ-92 pistols in not only 5.8x21mm but also 9x19mm (more on that later). The QSZ-92 is currently replacing the old Type 54s still in service.

The 5.8x21mm is important because it is the first small-bore, high-velocity round to be adopted by a major military power on a large scale. Whether its terminal performance is adequate remains to be tested in actual combat.

Strengths: armor-piercing ammunition standard, mild recoil, very good accuracy, high magazine capacity, very good penetration of soft body armor.

Weaknesses: unknown outside of China, potentially poor terminal performance.

7.62x25mm
First fielded by the Soviet Union in 1930, the 7.62x25mm has seen extensive combat over the years in both submachine guns and handguns. Replaced by the 9x18mm in Soviet service in the 1950s, it soldiers on with the People’s Liberation Army of China. Although currently being replaced in Chinese service, 7.62x25mm Type 54s will no doubt be fielded well into the future with certain PLA units.