JDG, if you have children in the house I plead for you to stop doing this NOW!
If you have kids in the house, not just the basement, they WILL have lead (and other chemical) related exposure health effects. Adults too. Even very low levels of exposure can result in cancer, reduced IQ, learning disabilities, attention deficit disorders, behavioral problems, stunted growth, impaired hearing, and kidney damage. At high levels of exposure, a child may become mentally retarded, fall into a coma, ect.... It takes a significantly greater level of exposure to lead for adults than it does for kids to sustain adverse health effects. You may think there's not much but most clinical symptoms of lead poisoning begin at only around 100 ppb and the effect on children's IQ has been noted at very low levels.
If I were you I'd not let my children in the basement ever again, I'd wear shoes in the basement and take them off just before entering the main floor, I'd stop shooting in the house immediately, and I'd call the state to find out who could professionally come out to the house and clean it up for a decent price. I hate to be a downer, but this is just not smart.