The Tirmax is a handy little carbine made between 1909 and 1914 in Liege by a German company. It is a semiauto action using a 5-round detachable magazine. The guns are quite scarce today because only a fairly small number appear to have been produced before World War One ended its manufacture.
Mechanically, the Tirmax is simple blowback, although incorporating a heavy hammer spring into the system to increase the bolt’s resistance to opening when fired. The hammer also has a lever extension on the left side of the receiver, allowing it to be manually cocked prior to manually cycling the bolt.
Out on the range, this particular example exhibited a bunch of problems, although that may or may not be representative of overall production. In addition to feed problems, I had one instance where the firing pin appears to have stuck in the forward position, resulting in 3 rounds slam firing in extremely fast succession – note that this is part of why one does not put one’s hand over the ejection port! After that incident, I stopped firing and the gun’s owner will have it looked at by a good gunsmith.