I have a really hard time with 2 and 3. Have you ever broken these weapons down? Do you actually go shooting? Have you ever machined anything yourself – particularly gun parts?
If you said no to any of these I really don't think you should be citing those. The only people who would have any business citing those facts would be the soldiers or engineers who designed or used those weapons. Everything else is conjecture from arm-chair gun experts.
To your face
http://www.gunpics.net/german/g43/g43dis.html
http://www.gunpics.net/russian/svt40/svt40dis.html
Every weapon in existance even the ones from 1300s are recorded piece by piece for knowledge keeping.