Gun homicides and gun ownership listed by country | News | guardian.co.uk
TL;DR:
United States 9,146 deaths by firearm.
England 41
United States % of Homicides by firearm = 60%
England % of homicides by firearm = 6.6%
...and these stats are from a globally distributed newspaper, not a 4 year old article off the website of an Australian gun club.