Be careful with some of the other brands of "dummy" ammo -- if they have an open primer hole then you still won't be able to dry-fire your older revolvers. These have what looks like a hard rubber plug in the primer hole (or maybe the plastic is just painted a different color). Either way, they do the trick and we can practice with the speed loaders and trigger control at home without using our ammo stock our paying a range fee. Just remember safety first. Remove all live ammo from your practice area. Double check and then check again to make sure you have no live ammo. Always keep it pointed in a safe direction even if you *think* you know it is not loaded with live ammo.  We like to practice in front of a mirror so we can better see what we are doing.