A firearm has a frame, a barrel assembly, a slide assembly which holds a recoil assembly, and a firing system with a trigger assembly and safety mechanism. The slide and recoil assemblies are located above the barrel so that the barrel is situated between the topmost part of the frame and the bottom of the slide assembly. The barrel assembly includes a housing which is covered by the slide assembly and secures one side of the recoil assembly. The barrel can be removably connected to the frame through front and rear mounts with removable pins and can modularly connect with the frame and slide assembly so that different caliber barrels can be interchanged. In addition to the trigger, the trigger assembly has a hammer, a sear, a lever arm that engages the trigger, sear and hammer, and springs that bias the trigger assembly components.

A gun barrel that has a proximal chamber end, a distal muzzle end, and an internal bore bounded by a bore wall, the internal bore having a first rifled bore section proximate to the proximal chamber end of the barrel, a second rifled bore section at the distal muzzle end of the barrel, and a reducing section distal to the first rifled bore section and connecting the first rifled bore section and the second rifled bore section, wherein at least one of the first rifled bore section and the second rifled bore section have straight groove rifling.

Improved firearms including one or more of a removable and/or interchangeable top cover, an improved extractor mechanism, a striker safety mechanism with a direct trigger interface, a sear with direct striker interface, and/or a striker with integral striker spring retention features.

A modular handgun system comprises an elongated universal trigger frame having a barrel locking block, a pair of slide rails, and an accessory rail. The trigger frame is adapted to have a trigger assembly mounted thereto. The system further comprises a grip frame having an elongated channel and a hand grip extending downwardly from the elongated channel. The trigger frame is removably mounted in the elongated channel of the grip frame. The accessory rail of the trigger frame is positioned forward of a forward end of the elongated channel of the grip frame so as to be exposed. The system further comprises a slide and barrel assembly slidably mounted on the slide rails of the trigger frame.

A firearm assembly including a receiver, a barrel, a locking block and a slide configured to provide rapid changing of a barrel of a handgun wherein the barrel may be for an alternate caliber round of ammunition. The locking block is configured to be secured within the receiver and includes an upper surface that has front rise member, a rear rise member and a valley intermediate thereto. The upper surface of the locking block is mateably shaped with the second portion of the barrel, in particular the lower portion thereof. The lower portion includes a front shoulder member, a rear shoulder member and a notch formed therebetween wherein the notch is configured to mateably engage the rear rise member of the locking block. The slide of the present invention includes a void intermediate the sidewall and the extractor housing. A shim is provided to be secured within the void.

A gun barrel that has a proximal chamber end, a distal muzzle end, and an internal bore bounded by a bore wall where the internal bore has a cartridge chamber at the proximal chamber end of the barrel, a first rifled bore section distal to the cartridge chamber, a second rifled bore section at the distal muzzle end of the barrel, and a reducing section distal to the first rifled bore section and connecting the first rifled bore section and the second rifled bore section.

Disclosed is an accessory attachment system for a slide-action handgun having a slide cover with side holes, a mounting flange, and a flange lock pin. The slide cover includes a front end, a rear end, an upper surface, a right and left side that cover a slide mechanism of the firearm. The mounting flange is inserted into the upper surface of the slide cover for receiving and securing a handgun accessory. The mounting flange has a bottom surface configured to secure the accessory attached to the mounting flange to the underlying slide mechanism of the slide action handgun using the flange lock pin.

A modular handgun system comprises an elongated universal trigger frame having a barrel locking block, a pair of slide rails, and an accessory rail. The trigger frame is adapted to have a trigger assembly mounted thereto. The system further comprises a grip frame having an elongated channel and a hand grip extending downwardly from the elongated channel. The trigger frame is removably mounted in the elongated channel of the grip frame. The accessory rail of the trigger frame is positioned forward of a forward end of the elongated channel of the grip frame so as to be exposed. The system further comprises a slide and barrel assembly slidably mounted on the slide rails of the trigger frame.

A mounting mechanism has a base upon which a rotating cam is mounted. The cam has a lobe which extends beyond the perimeter of the base when the cam is in a first position and remains within the perimeter of the base when the cam is in a second position. A detent is used to lock the cam in the first position. The detent includes a leaf spring positioned on the cam which defines a kink. The kink is engageable within a niche in the base when the cam is in the first position. An accessory attached to the mounting mechanism may be attached to a structure using the mounting mechanism. The base fits within a slot in the structure and the lobe of the cam engages the structure when the cam is in the first position to lock the mounting mechanism and the accessory to the structure.

Improved firearms including one or more of a removable and/or interchangeable top cover, an improved extractor mechanism, a striker safety mechanism with a direct trigger interface, a sear with direct striker interface, and/or a striker with integral striker spring retention features.