Took a friend shooting for his first time ever and we went to Silverdale, me as a guest with another friend who is a member and the new shooter as a non pal guest shooter.
One of my 9mm reloads (luckily the last one loaded in a mag) either had NO powder or not enough powder in the case. I shot the round and found it odd that the slide didnt lock opened but shrugged it off and put the gun away. We then went and shot some rifles. After the rifles we went to another hand gun range (the action range) for some close up shooting and by now my buddy was comfortable putting the mags in the guns himself. The gun wouldnt fully chamber the first round so we tried a second mag thinking it was one of the reloads not chambering correctly. Finally, I had a look down the barrel and saw it was fully obstructed. LUCKY for his hands and my face (standing right beside him watching him closely) the squib round didnt go far enough down the barrel to allow for a second round to fully chamber.
This was a very important lesson for me and because of it, I now pay much closer attention to the recoil I feel after each shot, and do not allow my friends to do any rapid firing at all. I also explain this same story to all the new shooters I bring out for a fun shoot. Not to mention I pay closer attention when reloading.