Abstract: An improved non-tilt barrel for converting a conventional semi-automatic weapon from having a pivoting linkage between the barrel and the receiver to a weapon having a cam in order to reduce the recoil of the weapon and to increase the accuracy of the weapon. Further, the non-tilt barrel is provided for increasing the distance of travel of the barrel during recoil to, in turn, increase the time of lockup between the barrel and the slide during the firing of a cartridge. As a result of the modifications resulting in the non-tilt barrel, internal pressures are reduced during the unlocking of the barrel and slide, thereby accomplishing a longer life for each component, and especially the recoil buffer pad. The position of the slide stop on a conventional firearm is moved slightly up and toward the rear of the gun. The length of the slide stop lever is varied accordingly such that engagement with the slide stop plunger is maintained in conventional fashion.