I was at the local range to pick up some snap caps for the M&P and one of the SRO's at the counter told me a short story. The had thought snap caps were worthless but he recently broke the firing pin of his handgun. He now has to buy and replace his firing pin AND buy some snap caps. But one thing he said is that he dry fired around 300-400 times a day. So next time you have a dry fire session or see snap caps at the store, you might consider buying some.