I got these to teach a friend to properly and quickly use a speed loader, or load their revolver one round at a time, without having to use fired brass.  For that, they work great.  They are very close to the weight of a 38 special round, so training feels realistic.  The primer area on these are a hard rubber, so the firing pin will not get damaged in a dry fire.  I have heard stories of their finish wearing off, but mine are still going strong.

Do I recommend them?  Sure.  For $15.00 or so, you get hours of training and practice.  Hopefully we do not have to use this practice in a defensive situation, but if that happens, I am sure $15.00 for potentially lifesaving training would be well worth it.