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You asked essentially how many violent crimes were presented by gun owners. Kleck did the best study to date on it and published in a peer review journal. The media doesn't bring these statistics into the conversation, which is why you wouldn't have heard about it.
Kleck conducted a national survey in 1994 (the National Self-Defense Survey) and, extrapolating from the 5,000 households surveyed, estimated that in 1993 there were approximately 2.5 million incidents in which victims used guns for self-protection, compared to about 0.5 million gun crimes as estimated by the National Crime Victimization Survey.