I remember reading that British testing done in the early days of WW2 showed that 22 rimfire would penetrate the German field uniforms and travel into the body far enough to do great damage out to at least 200 yds.
Interesting -- know why they were testing 22lr?
They knew the Germans were planning an invasion of England and it would be a tooth and nail fight to stop the Germans. Any thing, any way, every small cut bleeds the beast and enough small cuts can change it's mind and stop it or make it weak enough to finish off. Sort of like the US bombing campaign during WW2. We didn't bomb just the air fields, army bases, navy bases, etc. We worked over the factories that made parts/pieces (as well as the tanks, trucks and planes) and the rail ways (bridges, tunnels, stations/stops with lots of side tracks were train loads of supplies were staging, etc.
England does not have a Second Amendment and even back then not a lot of the common people (who would be fighting alongside the military) had center fire battle rifles. They actually asked us to send whatever we could (American civilians) to England to equip their people with center fire rifles. People donated their hunting rifle and shotguns, etc. that were shipped over there for possible use. At the end of the war most of them were collected and destroyed by a government still afraid to allow their citizens the use of fire arms.