That's not a very good argument - those guns are concentrated in the hands of about 32% of the US population [0], whereas in Canada it's probably closer to 25% [1]. [1] says "[t]he overall rate of firearm ownership is at least 241 per 1,000 population and is comparable to ownership rates in other countries where hunting is a significant activity"
[0]: https://news.gallup.com/poll/264932/percentage-americans-own... [1]: https://www.justice.gc.ca/eng/rp-pr/csj-sjc/jsp-sjp/wd98_4-d...