The KAC SR-16 is a AR variant carbine manufactured by Knight's Armament Company (KAC). It is a select-fire rifle chambered for the 5.56x45mm NATO cartridge. Being a select-fire rifle, it is unavailable to the civilian market.
The SR-16 is a lightweight, magazine-fed, gas-operated, air-cooled, and shoulder-fired carbine. It features a 14.5 inch chrome-lined, ball milled, lightened barrel, and uses a mid-length gas system. Like the AR-15, it features an inline gas piston system which operates on expanding gas, using the pressure generated by the gas inside the hollowed-out bolt carrier to cycle the weapon. It features the KAC improved E3 bolt and barrel extension for greater parts life, and the improved bolt carrier (termed "Carbon Cutter") which is more resistant to fouling in adverse conditions. The SR-16 also features a pressure reduction buffer to reduce vertical recoil, a two stage match trigger, ambidextrous controls (magazine release, bolt release safety switches), and a CTR style collapsible stock. It also comes with the URX rail (Upper Receiving Free Floating Rail System).
Manual of arms
The SR-16 is a lightweight, gas-operated, magazine-fed, air-cooled, shoulder-fired weapon. They feed from box magazines, most of which are either the 20-round or 30-round variety (each variety, save for the 5-round magazines, should be downloaded by two rounds - 28 for 30, 18 for 20, etc. This makes it easier to load on a closed bolt). The magazines are the same magazines that the AR-15 uses.
SR-16 rifles feature a bolt catch mechanism that holds the bolt open upon firing the last round in the magazine.
The magazine is inserted straight into the magazine well, and firmly pushed until a "click" is heard. Give the magazine a slight tug to make sure it does not come out. If the bolt is locked open, simply press the serrated "paddle" portion of the bolt catch in with the thumb to close the bolt and chamber a cartridge. If the bolt is closed, pull the charging handle to the rear and let it slingshot forward. The forward assist should not be needed unless the weapon isn't properly lubricated and is dirty.
At this point, turn the selector switch to the mode of fire of choice (semi, auto), and fire the weapon.
Once the magazine is empty, the bolt will lock open. It is good practice to always check the chamber for any obstructions prior to reloading.