Between August 1982 and January 1983, 1,874 felons in 11 State prisons in 10 States completed self-administered questionnaires focusing on their acquisition and use of guns before their imprisonment. The men were all serving time for a felony conviction dating after January 1, 1979. The States' and felons' willingness to participate were the only selection criteria, except in the 3 sites in which the eligible population was over 400 and in which random sampling was therefore used. Analysis indicated that three-quarters of the men had owned at least one gun in their life and just over half of the men were armed during the crime for which they were in prison. Having and carrying firearms was a central part of their daily existence, in part because of their concern for survival in a hostile and violent world. Gun theft had a critical role in the firearms supply for these criminals; from 40 to 70 percent of weapons used in committing crimes were stolen or borrowed from others. Only about one-fifth of the most recent weapons were purchased from legitimate retail sources. Findings called into question some commonly advocated policies about firearms purchasing regulations and indicated that these policies may prove to have negative and unwanted side effects. Data tables and a bibliography listing 40 references are supplied.