Just passing on advice I got when I made a similar post. In my first couple of sparring sessions, I was unable to land a hard punch. It'll come for you though. The best advice I got on here about this topic was to focus on your range. Your punches are landing lightly most likely 1. because your sparring partners are moving as you hit them, therefore taking away some of the impact when you hit them, 2. your range is off, you might be possibly hitting them with the tail end of your punches, 3. just plain old lack of experience. It took me 4 or 5 sessions to land that first booming punch. When it finally does land, god damn is that a good feeling . Now, after about a month of sparring a few times a week, more and more punches are landing for me, and I would assume that you will find the same as time goes on. Good luck man, and let us know when you finally do land that rockin punch .