The ENARM Pentagun is a prototype Brazilian semi-automatic shotgun.
This rather interesting revolver-shotgun hybrid was the brainchild of three men originally from a company known as BERGOM, who came together and formed the short-lived ENARM (Empresa Nacional de Armas) to design and produce this shotgun.
The entire design process for the Pentagun took approximately 10 months, and was expected to enter certification tests with the Brazilian Army in 1987 and to enter mass-production in approximately 1988.
The weapon was said to work adequately to justify its submission to said certification tests, but unfortunately, the tests never happened; debacles later occurred within ENARM and the company's partners and the company folded shortly after, putting an end to the Pentagun. Only one prototype was built before the company shut down.
The Pentagun looks rather similar to the LAPA FA-03, coincidentally also designed by Nelmo Suzano. The weapon has an inverted cylinder that holds five shells. Reloading the weapon involves breaking the weapon in two, like a double barreled shotgun; this involves the user operating a retaining latch which allows the weapon to be broken into two. When the weapon was loaded, the barrel assembly was pushed back up with the retaining latch locking it into place; ejecting spent cases from the weapon involved pulling back the crescent-shaped handle located inside the carry handle. Speedloaders for the Pentagun were also manufactured to ensure that the weapon could be reloaded quickly.
Construction of the weapon is mostly of polymer. It has been stated that the weapon is able to chamber 20 and 28 gauge ammunition simply by changing the barrel and cylinder. An LED light is located inside the weapon's tubular sight and can be turned off if need be via a toggle switch located in the hand guard. The LED light is activated whenever the trigger is pulled via means of a micro-switch located behind the trigger, and is meant for use in low-light conditions. The weapon featured a "straight-line" configuration which allows for minimum muzzle rise when firing, as with most of Suzano's designs.
When the trigger is pulled, the cylinder is unlocked from position, with the hammer moving rearwards; on trigger pull, the weapon's LED light will be activated. The cylinder first revolves anti-clockwise with the hammer still traveling rearward. Once the cylinder moves one-fifth of a revolution, it is locked in place with one chamber aligned with the barrel breech. A rod that is attached to the trigger and runs inside the handguard then pulls the barrel about 1.5 mm (0.059 in) backwards and forces the rear end of the barrel into the mouth of the aligned chamber to make a gas seal; the hammer will then be released and fire the round. When the user releases the trigger, the cylinder returns to its original position. To achieve the break-barrel reloading process, a roller-link chain section was added to said rod attached to the trigger.
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