The proof is the numbers.
the murder rate in the UK is actually twice what it was in 1950 BEFORE the gun control acts started being passed in the late 60's.
Murder rate in the Uk 2022 1.19 per 100K
The homicide rate in England and Wales for 2024/24 was 9.7 homicides per million people.
www.statista.com
Murder rate in the UK 1959 .6 per 100K
List of countries by intentional homicide rate by decade - Wikipedia
If gun laws actually reduced the murder rate as you claim it does then the murder rate today on your little island should be less than it was BEFORE all those gun laws you love were passed.
Guess what it's actually DOUBLE what it was in 1959