Demibloc barrels are a coupling system used to produce over-and-under shotguns, a system that supposes the union of the two tubes in the area where the lumps will then be created. The term “demibloc” is linked to the production of luxury shotguns in England and Belgium, from the mid-19th century for about a century. The lumps is created from solid by milling, then deep drilling is performed, followed by turning at the customer's request, and lastly the milling of the lump area is performed.
For the demibloc barrels tempered 42CrMo4 is used as material.