”Nobody disputes (I don't think) tjat more people are killed annually with knives than guns.”

Well I dispute it, and so do the statistics! Guns are overwhelmingly the most common means of committing murder in the USA.

In the UK in 2017, there were 31 shooting deaths in a population of c. 64 million. In the US, there were 12,128 in a population of c. 326 million.

In the UK, we aren’t allowed to possess handguns or assault-type rifles. In the US, it’s “Ma-a-ah Right, aa-a-awdained ba-a-ah Aa-a-awl-ma-a-ahty Ga-a-ad in the 2nd Amendment!”, or some such horse-shit.

It really isn’t difficult to do the maths and understand the correlation.