If you have ever wondered a how loud a 40 S&W is when fired in an indoor range, well I have firsthand information that they are extremely loud. I put my hearing protection on when I entered the range today because there was another shooter. I setup my chronograph and was getting everything ready. He finished shooting and we struck up a conversation so I removed my “Ears”. Well he left I loaded my 40 Pro Series, touched off the first round AND WHOLLY MOTHER OF GOD I thought a bomb went off! So after my ears quit ringing I put my hearing protection back on and very gingerly squeezed off the next round.