 The Model L is a selective fire, roller-delayed blowback firearm.The weapon features a semi-rigid two-piece bolt mechanism that consists of a bolt head and a supporting angular locking piece.During the "unlocking" sequence, the two cylindrical rollers contained in the bolt head are cammed inward against inclined flanks of the barrel extension and act upon the locking piece and bolt carrier, propelling it rearward at a velocity greater than that of the bolt, which remains closed until the fired bullet has left the barrel and pressures inside the bore have been reduced to a safe level before withdrawing together with the bolt carrier.