The Soviet Union issued instructions on the vulnerable points on a tank to rifle fire. This included both firing slits and optics. This is covered in a new Casemate book: World War II Snipers French & Indian War technology can still be effective (as is the entrenching tool) as a CQB weapon. The trick is not to let the other side get that close (unless you have Jet Li level martial arts skills). BTW: Had a guy swing a 6' stick like a baseball bat at me once and I swung a side handle baton one handed to block it. It knocked the stick out of the guy's hand and I bent over laughing as he fled. I don't have Jet Li level of martial arts skill.