The Canadian figures are here:

http://www.rcmp-grc.gc.ca/cfp-pcaf/facts-faits/archives/quick_facts/2011/dec-eng.htm

According to the RCMP, the 33 million Canadians own about 8 million registered guns.

According to the USDJ, in 1995, 300 million Americans owned 223 million guns:

http://web.archive.org/web/20071214070953/http://www.ojp.usdoj.gov/bjs/pub/pdf/guic.pdf

(That number is presumably higher now. It's an old document but still informative.)

Maybe you're thinking of Switzerland. Every every adult Swiss male is required by law to own an automatic weapon and ammunition for national defense. Homicides in Switzerland are rare.

Antebellum Southerners certainly were afraid of slave rebellions, and on the Frontier you'd be crazy not to have a pistol to defend yourself. But research shows that the rate of shootings in places like Dodge City and Tomstone was nothing like in the movies.

But none of these facts explains the amazingly high rate of shootings and gun homicides in the United States. I haven't checked, but I believe it began early in the 20th century. Overall rates of violent crime really took off in the '60s, but have been dropping for about twenty years.