Smith & Wesson M&P 15 is an AR-15 style semi-automatic gas-operated rifle and one of the top choices in the AR-15 market, shooting 5.56 mm NATO and .223 REM caliber, with 10 or 30-round magazine capacity for standard models (10-round in states with restrictions). There are also available variants that shoot .22 LR or 5.45x39 calibers. It was introduced in 2006 and is offered in many different configurations to adjust to specific shooting styles (currently, 24). The threaded barrels are made of chrome-lined 4140 steel, with an Armornite finish. The barrel twist is 1:7, 1:8, or 1:9. There are many features on this rifle, like – a free-float handguard with M-LOK slots, an adjustable arm brace with closure strap, a full-length Picatinny-style rail, a one-point QD sling swivel attachment point in the arm brace, chromed firing pin, and forward assist button. There are also 4 interchangeable palm swell grip inserts and a forged integral trigger guard. Some other features are a dust cover, optics, and manual safety. This is a very powerful, tough rifle ideal for any purpose, depending on the exact model you choose.