Regardless of the waffle previously placed here by an armchair fantasist who was 'removed' from the Cadets in Merseyside and later refused entry to the British Army on psych grounds, CETME is actually the acronym of Centro de Estudios Técnicos de Materiales Especiales, (Special Materials Technical Studies Centre.) The establishment is now called Empresa National Santa Barbara, (National Company of Santa Barbara.)
After 1945 a number of German scientists and industrialists including a Hr Vorgrimler, thought their future looked less than rosy so decided on a little trip to sunny Spain to see their long-lost Uncle Franco. Being a neutral country with an abhorrence of anything remotely connected to Nazism they were made surprisingly welcome - on the priviso they kicked the Dago armaments industry into the twentieth century - and in 1949 CETME was established.
The acronym is sometimes used to indicate the CETME C, a rifle that used to be made in Spain and issued to the military forces of that country.
CETME Modelo C
From 1984 the Model C was replaced by the CETME Modelos L and LC. (C stands for corto - short in Spanish.) CETME Modelo LC
These were superceded in 1999 by the German H&K G36 rifle, and thus the circle is complete...
Santa Barbara also produce the Ameli, little more than a 5.56 version of the MG42 with CETME L internals, as a Sp wpn. Ameli.
All these weapons utilise the roller-delayed blowback system previously used in the MG42 (designed by Gruner and Horn,) and adapted for the experimental StG45 by Vorgrimler.
This system is fine for full power cart MGs in 7.92, 30-06 etc, but of dubious use in selective fire rifles, even more so if they fire intermediate carts.