Simunitions are valuable training aids but they are old news. The best I have come across and currently use are known as UTM rounds. They have longer accuracy distances and also offer different types of rounds for different type scenarios, such as silent blank rounds that will cycle your bolt/slide, blanks that you can have contact with the target and not hurt the other person. The man marker rounds still hurt, just not as bad as sims do and offer realistic trajectories, no curve balls or whacky trajectories that you get sometime with sims. Plus there is absolutely no way you can accidentally shoot a live round when you have the UTM bolt in your weapon. So if you like Sims for Force on Force, check out UTM's products, you won't want to go back to Sims after you use them.
UTM Worldwide