A major problem with Simunitions is that it is expensive, costing three times more than real ammo. But for commandoes, it's worth the cost. Actually, it would be worth it to send all infantry through some training exercises with Simunitions. This is because the weapons operate and sound the same as they would in combat. The Simunitions bullets have a the same accuracy as a real M-16, up to about 25 feet, and a maximum range of about ten times that distance. Thus the Simunitions are most useful for training for fighting in urban areas. But this is the most difficult and nerve wracking form of combat, and giving troops the most realistic training for this would be a real life saver down the line.
But the success of Simunitions has made troops aware of the fact that many other weapons are not accurately represented in training. This is especially true of grenades (both hand and 40mm), RPGs and AT-4 rockets (and similar systems.) In Iraq, it was a jarring experience for troops who had practiced with Simunitions to find that, in real combat, there were all these other weapons they had to contend with. Two solutions have been proposed for this problem. The easiest one is expanded versions of the photo-realistic training games the U.S. Army is now using (like Full Spectrum Warrior). Including all the weapons and a wide variety of situations would enable the troops to play with (or "train") with all these other weapons in a realistic format. But this is not the same as actually going out and using the weapons.
Thus the other solution, the development of electronic grenades, rockets and missiles. This would involve wearing an electronic sensor and developing grenades, lower velocity 40mm grenades and RPGs that would, when they hit something, set off a loud noise and flash of light, then send an electronic signal that would indicate that troops within a certain range (unblocked by anything that would stop fragments) that they are hit. This is similar to the MILES (laser tag) gear that troops have been using with rifles and heavier guns for over two decades. This stuff is still dangerous, even with all the troops wearing helmets, goggles and protective vests. But it's been found that the more realistic the training experience, the more effective the troops are in combat. This means defeating the enemy more quickly, and taking fewer casualties.
Another item missing, when using Simunitions, MILES and any other practice munitions, is the lack of physical damage. In combat, troops will use rockets, grenades and automatic fire to blast through doors and walls. When fighting inside buildings, firing through floors and walls is common. Experience doing this is very valuable. For the moment, the best way to demonstrate these weapons effects frequently, and at afford able cost, is with the photo-realistic simulation games. The army is also working on more immersive type games of a type that have not yet reached the commercial market. These involve wearing video glasses, headphones and movement sensors and literally acting out the operations. You get visual and aural feedback via the video seen on the glasses/goggles and headphones.
The more realistic training systems, starting with MILES and paintball in the 1980s, have led to a demand for more and more of it. This stuff is real enough to save lives and the troops want more of it. It's become obvious to professional soldiers world wide that the more realistic training gear delivers a very real edge in combat. This makes troops trained this way much more effective. Even armies of poor countries are trying to get this gear, because it is seen as more valuable than many other types of military equipment, or even additional weapons. But it's been true throughout the history of warfare; better troops are more useful than more troops.
Infantry training still suffers from the inability to accurately simulate the use of grenades, rocket launchers and machine-guns. For the last two decades, there has been non-lethal rifle ammunition that can be used with existing weapons. The most popular of these are Simunitions, which are low powered, paintball bullets. Users often refer to them as "soap bullets". Troops take apart their M-16s, and replace the barrel with a $700 Simunitions barrel that can handle the Simunitions rounds. When fired, Simunitions bullets will sting if they hit you, and leave a dye mark. With seven different dye colors available, it's possible to find out who shot who, and how much friendly fire their was. Actually, the Simunitions hurt a lot more than paintball ammo, and those participating in Simunitions exercises have to wear goggles and groin protectors. If you are also wearing your protective vest, that will take the sting out of a Simunitions hit, but for arms, legs and other exposed parts, you will have a nice bruise to remind you that more care should be taken to find cover on the battlefield. The Simunitions rounds contain less propellant that regular rounds, and leave the barrel at about 550 feet per second, less than a quarter the velocity of a lethal bullet.