If practicing trigger-squeeze etc, and dry-firing to do so, you want to insert an empty magazine, if I'm not mistaken. Dry-firing to unload, because you want to field-strip and clean, won't hurt the pistol; but I think dry-firing over and over as in practice can damage the firing mechanism. I'm sure if I'm wrong someone will correct me- some nicely- others not so much. As said before, just be sure and check that chamber - be positive it's empty- before any dry-firing. Check it two times- three times. Even experts have fooled themselves and had accidental discharges.