Before we focus on the unique features of the Rock River Arms LAR-15 QMC (Quick Magazine Change), let’s take a moment and acknowledge the rock-solid base this system is built around. The rifle has a forged upper and lower receiver with a 16” chrome-moly HBAR 1:9 twist barrel. This is fitted to the RRA Beast muzzle brake via standard ½-28 threads. The barrel is free floated via the TRO-STD octagonal handguard and low-profile gas system. This handguard even has a top rail machined into it for good measure. Included in the box are one long and two accessory rails that can be mounted based on your needs. The controls are pristine with a Hogue pistol grip, BCM gunfighter charging handle and an RRA Star safety/selector switch. The trigger is an RRA two-stage match trigger that breaks at 2 lbs. 12 oz. every time. This is surrounded by an RRA winter trigger guard that is as attractive as it is effective. All of this delivered less than one minute of angle with all the ammunition I fed through the rifle. Rock River did not cheap out with the accessories, either. The hard-plastic case will provide years of real use, unlike the cardboard box most rifles ship with today. You will find two magazines – one 30 round polymer and one 10 round metal, both sporting the Rock River brand. The whole rifle comes in at a respectable 7.9 lbs and stores in just 34 inches. There are four choices for sling mounting with two QD sling attachments and two clip-in sling mounts. The RRA MAG CAR stock has six positions of adjustment and storage for an extra magazine. Now, four reasons the QMC is the right way to carry an extra magazine. The addition of the RRA MAG CAR stock delivers a quartet of advantages: It doesn’t disturb the balance of the gun. By putting the loaded magazine inline as opposed to on one side it keeps the gun balanced. This keeps the natural balance of the gun. It duplicates the natural magazine change of an AR 15 by keeping the same controls. The action of ejecting the spent magazine and inserting a fresh one is habitual to many users. The act of retrieving a stored magazine can be less than smooth when absent a preferred chest rig or other specialized gear. By storing the extra magazine on the gun, while duplicating the controls and angle, it reduces the fumble. If you chose a 30 round primary in the gun and a 20 round in the RRA MAG CAR stock with an aftermarket base plate, it allows a supported prone shooting position without additional hardware. By storing the magazine on the rear of the gun it doesn’t change the profile of the weapon by increasing the width on the front of the gun. I mounted an Aimpoint Comp M2 with a 4 MOA dot on an A.R.M.S 17 mount. This would allow me to put the gun through its paces. The function and reliability of the gun were flawless no matter the ammunition of magazines fed to the QMC. The magic happened when it came time for a reload. When the bolt locks back you slide your left hand back on the forearm. Breaking your grip on the pistol grip, release the spent magazine with the magazine button on the lower receiver, grasp the extra magazine stored in the QMC buttstock with 4 fingers. Depress the magazine release, releasing the second magazine. Insert the fresh magazine into the empty magazine well. Reacquire your firing grip on the pistol grip. Release the bolt with the bolt release lever. Finally, position your left hand back on the forearm. This manual of arms takes a few repetitions before it begins to be ingrained. As I said earlier, we all have the ultimate chest rig or belt carrier we use on the range or in class. However, let’s face facts – a gunfight is a come-as-you-are event. If you have time to grab your rifle, chances are you will only have what is attached to the gun. The QMC rifle will assures a reload will always be within reach.