By surprisingly popular demand, here's a video about primary extraction, which is how a sticky case is shaken loose from the chamber after firing.

Featuring an M1 Garand, which has (almost?) no primary extraction, a Mauser Kar98k which has the most common type of cam-based extraction, a Lee-Enfield No.4 (NOT an SMLE), and a Swiss Schmidt-Rubin K31. The last of these is a straight-pull with a really, crazy powerful primary extraction based on helical locking lugs.

For the observant, this video is actually also a stealth Lee-Enfield No.4 vs. Mauser 98k video :D