Characteristic of Merkel barrels is the tapered form: the barrel narrows from the receiver to the muzzle by approximately ten thousandth of a millimetre. This prevents premature wearing of the barrel and enhances the precision of the shot. Merkel cold forging is based on four key technologies: deep-hole drilling, grinding, honing and annealing. Once the hole has be bored the grinding and honing follow, which produces extremely smooth inner surfaces in readiness for forging. These technologies, which are used in engine construction to finish the sliding surfaces of the cylinder, smooth the Merkel barrels to two thousandth millimetre exactitude, significantly increasing the service life and the precision of the barrel.
Forging is followed by stress-free annealing in a vacuum furnace. Inevitable stresses build up in the steel during forging, which are dissipated by this heat treatment over a period of several hours.