Looks like a Winchester saddle rifle--lever & hammer
A piece of small tube
The Mauser es340b was a single shot .22 long rifle. It was made too look and feel like a Mauser 98K. It is not a sniper rifle. It is a target rifle.
If you mean a .22 Long Rifle cartridge, see the link at the bottom of this page.
A google search will bring you pictures
Look on the butt.
a rifle looks like a pistol but longer and fatter
See the link at the bottom of this page for a good article on rimfires, with photos.
Look in gunpartscorp.com website
Start with a chunk of wood, several chunks of steel, and several thousand dollars worth of machine tools like lathes, milling machines and drills. Remove all the steel and wood that does not look like a rifle.
Uh, we don't use 22 caliber rifles for training anymore, they're kind of obsolete. The closest thing I can think of for you is a winchester, but it doesn't look like an M4 series..
Look on the receiver