The AR-15 type rifle is probably the most popular series of American rifles in a half-century. The proven, mature design, standardized feature set, and military-style cachet during a period of two simultaneous land wars combined to make the AR-15 the sporting rifle of the age. A vast and diverse market of AR-15s arose, aimed at high and low-end budgets. One rifle on the lower end of the budget spectrum is the affordable and capable Smith & Wesson M&P15  Sport II.

The M&P (“Military & Police”) Sport 15 II is an entry-level AR-15, and for this article, we’ll discuss the M&P 15 Sport II Optics Ready with M-LOK Handguard. This rifle is an ideal beginner’s gun, capable of being steadily upgraded as the user invariably explores the world of AR-15 aftermarket parts and accessories. The rifle barrel twist is set to use the most common inexpensive ammunition, and the weapon itself comes without sights, allowing the user to pick any one of literally hundreds of sights or rifle optics.

The M&P 15 is, like most AR-15s, chambered in 5.56/.223 and accepts standard M16/M4-style magazines. The rifle uses the direct impingement operating system, which cycles a portion of high-pressure gunpowder gasses through a tube that runs over the barrel, back into the weapon’s action, pushing back the bolt carrier group and ejecting the spent casing. As the bolt carrier group springs back forward, it strips off a fresh round from the magazine and goes into battery, leaving the only action left for the user to perform to fire the gun again to pull the trigger.

The M&P 15 is equipped with a sixteen-inch barrel, the minimum length for long guns not subject to the National Firearms Act. The barrel features Smith & Wesson’s proprietary Armornite finish both inside and outside, to ward off rust and other forms of corrosion. The barrel is also threaded and fitted with a standard M16-type flash hider. Finally, the barrel incorporates a one in nine-inch twist rate, meaning the rate of twist completes a revolution over nine inches of barrel. This is ideal for stabilizing 55-grain M193-type ammunition, often the most inexpensive of .223/5.56 ammunition types.

The M&P 15 features many common AR-15 features. The upper receiver features a dust cover to prevent dirt and dust from entering the action, as well as a shell deflector. It also features a forward assist mechanism for clearing malfunctions, though the AR platform’s reliability has arguably advanced to the point where the feature is no longer necessary. The trigger guard is swelled to accommodate gloved trigger fingers, and the rifle is sold with a standard A2-style pistol grip. Nearly any of its parts can be swapped out with improved versions, either by a gunsmith or a safety-minded user with the correct tools.

Smith & Wesson’s entry AR-15 may be for beginners, but the modular nature of the AR platform means it can scale up as the user purchases more aftermarket parts. The optics-ready version of the rifle lacks not only a front sight base but rear backup sights, instead featuring a Picatinny-rail on the upper receiver. This allows the quick installation of a relatively inexpensive (or expensive) red dot or holographic sight, or aftermarket iron sights. The Magpul MOE handguard allows accessories, such as lasers, flashlights, sling rings, and bipods that attach using the M-LOK mounting system to be quickly and securely fastened to the rifle.

The Smith & Wesson M&P15  Sport II rifle typically retails for under $800, and the addition of an optic or sights can quickly create a rifle tailored to the user’s needs. While inexpensive, the rifle uses a dependable, proven operating system that will absolutely work when needed. A wide variety of aftermarket parts and accessories makes for endless customization options, with a user only marginally talented with tools capable of transforming his or her rifle into anything from a designated marksman-style sniper rifle to a short-barrel rifle.

Kyle Mizokami is a writer based in San Francisco who has appeared in The Diplomat, Foreign Policy, War is Boring and The Daily Beast. In 2009 he cofounded the defense and security blog Japan Security Watch.