Invented for the German military at the turn of the century, the wide distribution of the 9x19mm Para(-bellum)/Luger cartridge made it the logical choice for the NATO standard pistol and SMG round. While weaker than .45 ACP, it tends to have an advantage in weight and capacity. Fairly good against unarmored personel, but non-efective against bodyarmor.
Si vis pacem, para bellum - if you want peace, prepare for war.

The standard U.S. pistol round for about a century. The .45 ACP offers more power than 9mm Parabellum but due to it's heavy weight and large size, it lacks the penetration and range of the 9mm. Very effective against unarmored personel but lack of penetration makes poor choise against bodyarmor.

Using a lengthened and strengthened version of the .38 Special case, the .357 Magnum was rapidly accepted by hunters and law enforcement. At the time of its introduction, it was claimed to easily pierce the body panels of automobiles and crack engine blocks. While it has less power than .44 Magnum, it compares favorably to the .45ACP, but with better penetration. .357 Magnum is also good against unarmored personel.

The trick with the buckshot is that you can have a few large pellets or a bunch of smaller pellets. The smaller pellets have a better chance of scoring a hit due to the sheer number of pellets, but the severity of the wound won't be as great as a hit from a larger pellet. For purposes of game play, the armor piercing shot will not be as effective as standard buckshot against non-armored targets. The standard buckshot is worthless against armored personel except for taking out the legs and arms, hoping for enough wounds to cause incapacitation.
The power of a blast of buckshot is equal to 10 rounds of 9mm bullets.

Adopted by the US military in the 1960s, it later became the NATO standard rifle cartridge in the early '80s, displacing the much more powerful 7.62x51mm. The small and light bullet is prone to many enviromental variable like the wind; the 5.56mm has triple the wind drift of the 7.62mm. Also the early versions of the 5.56mm used a wrong type of gunpowder that caused a lot of weapons to jam. But the 5.56mm is a good round for many assault rifles. It's good against personel, but has trouble with heavy bodyarmor.

This was the standard NATO rifle round until it's gradual replacement by the 5.56x45mm. It is much more powerful than 5.56mm, but has considerable more recoil. It is now typically restricted to sniper rifles and Machineguns. Good against personel, with lots of penetration.

The standard Soviet rifle cartridge from the mid-1940s to the mid-'70s, it is easily one of the most widely distributed cartridges in the world due to the distribution of the AK47 series. Roughly equal in terminal performance with the 5.56mm NATO, it is far less powerful than 7.62mm NATO. Good against all personel, but has trouble with heavy bodyarmor.

The Soviet's response to the 5.56x45mm cartridge. The long (almost 1 inch) 5.45mm projectile doesn't fragment like the 5.56x45mm. Good against all personel, but has trouble with heavy bodyarmor.

The M406 uses an alloy projectile body to support a nose impact fuze and a spherical prefragmented steel container holding the bursting charge. The fuze magazine protrudes into the fragmentation container so as to initiate the high explosive. The aluminium cartridge case is semi-rimmed, with a percussion cap pressed into the rear. Forward of this cap, the interior of the case is shaped into a small propellant chamber which is provided with vents to the remaining space within the case. On firing, the propellant burns inside this chamber at high pressure, and the gas vents to the interior of the cartridge case where it expands to provide a low-pressure impulse to the projectile. The case is crimped to the projectile body allowing pressure to build up to approximately 3,000 lbs/in{2} before the projectile pulls free. This provides a degree of consistency in chamber pressure and velocity. The M551 fuze is a direct action impact fuze with delayed arming.

The M433 are fired from the weapon by a percussion primer, and use an internal PD fuze to function upon impact. The color coding for the M433 is an olive-drab cartridge case with yellow markings and a yellow ogive. It is designed for use against armored targets, and has the additional capability of inflicting personnel casualties in the target area. This is the usual fixed round, with the projectile composed of an aluminium body with driving band and a hollow aluminium nose cap. The body holds a shaped charge with a copper cone liner, and ahead of this protected by the nose cap. This fuse has delayed arming and, when functioned on impact, fires a small shaped charge in the fuze magazine. This directs its jet backwards to strike a detonating unit located at the apex of the shaped charge cone. This detonates and initiates the shaped charge filling, the energy from which is directed forward to the target.

The weapon of choice is the 20mm grenade launcher as this reduces target errors (misses) by using a programmable munition. The point where the munition explodes is set on firing by a laser rangefinder. Electronics in the 20mm munition count the number of turns as it spins. A certain number of turns is equivalent to a certain distance. The grenade normally arms at 25 metres, this is the minimum range before the warhead detonates. In the short arm mode, this decreases to 14 metres, but this may be overriden to 5 metres for close range work. The mode must be set before the grenade is fired, and can not be changed. Most battlefield targets are exposed (no cover), protected (trench, etc), fleeting (crossing a street) or are behind cover (no direct fire weapon can defeat these, besides penetrating) and the 20mm grenade should defeat all of these. Effective against personel and light armored vehicles.

RPG's were primarily intended as a light anti-tank weapons, but in Vietnam and elsewhere since, they have been used as a very effective psychological terror weapon because of the tremendous blast and noise. The rocket is a thin metal skinned shaped charge that will penetrate light armor from 6" to 14" thick. Used against ground troops and bunkers, it was effective in direct hits, but there was not much schrapnel unless one was near the point of impact. The RPG-7 rocket has no fins and is gas stabilized. The 40mm HEAT rocket grenade has an effective range of 300 meters against moving targets and up to 500 meters against stationary targets. The projectile explodes either on impact or at its maximum range of 920 meters. Good against personel and armored vehicles.