I've been shooting and running competitions for a long time, formally since 1973.
Never had a serious accident on the range, but I will say I'm pretty nasty in regards to safety. I get real uptidy.
Closest I can think of is in the old days when we used paddles to mark shots and scores in HP. The got shot and spattered splinters on the guys in the pits.
Also happens when some one hits a spindle. I require eye protection for pit crews.
Other then that, I was working with 4-H kids and air guns. The club used huge tires as back stops. A pellet bounced off a tire and hit a kid in the knee leaving a slight red mark.
Don't use tires and back stops and always WEAR EYE PROTECTION while on any range.
As a side note, I was practicing in my back yard shooting steel plates, A piece of lead came back and inbedded in the lense of my shooting glasses.
Other then eye protection all other accidents can be avoided my the 4-simple safety rules, or if not avoided, nothing or no one gets hurt.
Stuff does happen, for example I had a wad gun (38 wc pistol used in Bullseye) that would double every now and then. The results of those accidents was a bad shot, costing points but since the pistol was pointed down range, nothing or no one hurt.
As a side note, I do required ECI (empty chamber indicators) on any rifle not actually being fired.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071