CETME is an acronym for Centro de Estudios Técnicos de Materiales Especiales (Center for Technical Studies and Special Materials), a Spanish government design and development establishment. What does that mean? Well, they made a rifle, which just happens to be their most famous project.
This video tutorial will show you how to correct the bolt gap and lockup in a CETME rifle. If you know nothing about the CETME rifle, maybe you should go get the firearm, so you can learn. Then learn how to field strip the weapon, and learn how to correct the bolt gap and lockup in a CETME rifle, to reset your bolt gap.