I personally advocate evidence-based approaches to reducing gun crimes, yes. However even if we exclude guns, when I’ve previously looked at knife crime rates between US and UK, US was still was higher.
The non-gun murder rate in the US is about double that of the UK.
I think the difference in the gun murder rate reflects other legal differences, such as those around carrying and storing guns more than the level of ownership. If you have to go home and unlock a safe to get a gun it gives you lots of time to cool down.
This is but one crime, but the homicide rate in the US is 5.9 per 100k, which is about 10x higher than in Korea.