The gun homicide rate in the US is 4.5.
The US has roughly 110 guns per 100,000 people and 4.5 gun homicides per 100,000 people.
Mexico has over 20 gun homicides per 100,000 people and about 18 guns per 100,000 people.
Canada has 2 gun murders per 100,000 people and 31 guns per 100,000 people.
Mexico: each gun is responsible for 1.11 murders
US: each gun is responsible for .04 murders
Canada: each gun is responsible for .07 murders.
Interestingly, the Bahamas has 30 gun murders per 100,000 and about 4 guns per 100,000. That's 7.5 murders per gun.
France has 2.8 gun murders per 100k and 31 guns per 100,000. Which makes each gun responsible for .09 murders -- slightly higher than both the US and Canada, despite far stricter laws.
The U.K. Has .23 gun murders and 6.6 guns -- so .35 murders per gun.
Sweden has 1.47 murders per 100k with 31.6 guns for a rate of .047 murders per gun.
Nicaragua has 4.68 murders with 7.7 guns -- each gun is part of 1.65 murders.
Jamaica: 31 murders/8 guns.
Denmark: 1.28/12 guns
Israel: 2.09/7.3 guns
Brazil: 21.2/8 guns
Australia: .93/21.7 guns
My point: gun ownership does not correlate to gun murder rates -- in fact one could make a case that increased gun ownership could actually reduce gun murder rates.
Despite having more guns per capita than most countries, the overall US murder rate ranks 108 out of 218, with Honduras topping the list (incidentally Honduras has 67 murders and 6.2 guns per 100,000)