Sorry, but they didn't.

I was a nurse for years working in people homes in the community. I met people who had de-activated guns brought back from the war, and shot gun owners, but the percentage of gun owners in the this country even thirty-forty years ago was tiny. The average family in a terraced house in Luton did not own a gun. Farmers did, and they are the ones that still do.

Crime was smaller on all counts. Even if you look at the big crimes of the time when guns were easier to own, they were conducted without.
The driver in the case of the great train robbery was beaten to a pulp, not shot, etc.

Old ladies didn't even lock their doors at night forty years ago, and they didn't all have guns. And there are people who didn't lock their doors twenty years ago either. The rise in crime statistics is much sharper in more recent years, not this big jump as soon as gun control was brought in.

The biggest risk in robbing someone was the fact that they might well know you. Communities were smaller and tighter knit, and chances are you could identify your burglar, or at least see your goods in the pawn shop or someone else's living room the next day.