'It seems that despite the strict gun control policies in the United Kingdom, criminals are still getting guns. In fact, police recently uncovered an illicit gun factory.' When you create a black market.... Source:https://bearingarms.com/tom-k/2018/08/24/illegal-gun-factory-found-uk-impossible/
Yes, gun making is not rocket science. 10 year olds manufacture machine guns in 3rd world weapons shops.
Who cares about small garage factories when the English vets who returned from war brought even friken missiles from Iraq. London is often called "Land of the UZIs" here in Bulgaria. Because there -- you have more illegal UZIs than bread.