I was really excited this weekend. I was going to finally get to sight in my new AR-15: http://www.firearmstalk.com/forums/f20/first-ar-15-build-here-i-go-28708/ But it didn't go quite as expected. My father-in-law has NO experience with handguns (only hunting rifles and black powder) and I didn't take the 10 minutes with him again like I did last time we went shooting. And he forgot a few basics. He has big hands and we were shooting my Kahr PM9. At the beginning of our range session, which I thought would last a couple of hours, his left hand was holding the small handgun kind of like a rifle (ARRGGGH!) and his left index finger was in front of the muzzle. I yelled STOOOOOOOOPPPPPPPP!!!!!! And he readjusted. Whew. I watched his support hand hold it correctly this time. My eyes then shifted to watching his trigger finger. He slowly pulled the trigger very well, the gun fired, he lower the gun and it was starting to point an unsafe direction and I got hot and bothered again. I took the gun, cleared it, put it down on the table. Well, he was holding his left hand, which had a huge, deep gash in the web of the left thumb. He had brought his left thumb around the back of the gun and the slide bit him HARD! I had to go into first aid mode, get the bleeding stopped, plus clean up our firearms and ammo, which we had all spread out for a long range session, so we could get to the emergency room. BTW, this range's first aid kit was WAY inadequate. Either it had been used up and not refilled, or was never good to begin with. I will probably toss a complete first aid kit (heavy on blood absorption) into my range bag for the future. 2 hours later, he had gotten 5 stitches at the Emergency Room. I thought I could hand him a handgun because he is a "gun guy." But we must be absolutely sure that our guests are COMPLETELY taught about process, safety, and function of our firearms. He knows how to load a musket. He can bag and dress an elk. But handguns are NOT his bag. I had spent time teaching him handgun protocol eight months ago, but I shouldn't assume he remembered. My bad, big time! He almost shot his finger off AND he sliced open his thumb. He will be okay so this a good outcome to a bad day. But this was definitely a range session none of us want to have.