They're in all my semi-autos (4 Glocks [17,19,20 & 40]). I use the Defenders because the penetration isn't too great. In my 10mm's it's 18" of ballistic gel. If the bullet has to penetrate heavy clothing and bones it may exit, then again it may stay in the bad guy's torso. I'm going to compare the penetration of Punch Bullets and Corbon FLN for my S&W 500.
