I would not dry fire a gun w/o a snapcaps.
U will undoubtedly get people telling U that dry firing any current designed semi-auto is fine. And, many people do it.
But, I have read so many consistent stories to the contrary. Beretta 92's breaking firing pins by doing this. HK USPs having the same issue w/ "excessive" dry firing (they recently redsigned the firing pin on the USP to try to stop this). Even Glocks, which you must dry fire to disassemble - Over the years, I have read several reports of cracked breach faces because of dry firing. These are just the ones I remember about right now.
Go spend the $10-$12 and buy some snap caps. Be aware that some guns prefer certain snap caps. I have a mixture of plastic and metal guns. My P99s do not like to chamber the metal ones - I have to use the plastic front ones.