I love my Hatsan Bullboss .25, but I find it to be one of the loudest PCP rifles that I own. This time of year all of my shooting is done in my basement range. The Bullboss is fine outdoors, even backyard friendly, but in the confines of the basement it seems loud. Or at least that is what my wife said. I decided to get a DonnyFL moderator for it. The Emperor V2 was on sale so I went with that. If I was carrying the Bullboss around it might be a bit much, but shooting off a bench it is fine. Wow, is all I can say .The ONLY sound now is the twang of the hammer and the whap of the pellet hitting the target. Outstanding.