This is an absolute must! I have shot many deer out of wooden shooting houses and making sure your barrel is outside the blind by at least a few inches is a must. The concussion the blast gives off is quite big, but most people never experience because they are shooting in an outdoor area. I accidentally had my muzzle inside the blind once when I took a deer, never again. You will know it if your muzzle wasn't outside the blind, your ears will be ringing for a while!!