If you are using jacketed bullets, 25 yds is the closest and you may still get piece of jacket that can cut you. For lead bullets, 10 yds is as close as you need to be. Still a chance to get nicked but not as bad as the jacket ones. Also depends on if the targets are falling ones, swinging, or stationary! I shot these type of targets for years in the IPSC/USPSA matches around the country and can't remember ever getting hit by fragments.