The original rifle was designed as a 300-yard rifle, but recent versions can “reach out and touch someone” out to 800 yards or more. AR-type rifles and carbines have become truly modular, although we know from conversations with Jim Sullivan that the original AR was never envisioned to become what it is today. The AR can be transformed simply by swapping upper receivers. It is even possible to switch calibers by changing uppers, as with the .50 Beowulf, 6.5 Grendel and 6.8 SPC.
A true cottage industry has developed for manufacturing custom-built ARs, catering to specialized customers. These manufacturers produce AR-type rifles and carbines, ranging from entry-level guns to very expensive full-custom rifles. One of the mainstays of the AR market is CMMG, a well-established and innovative manufacturer of AR-type rifles and carbines. They offer a complete variety of firearms to suit the needs of just about any user, from varmint hunter to SWAT team member, in either semi-automatic or select-fire.
For military and LE units that employ M4-type carbines, the matched pair of .223 and .22 LR carbines tested for this article are for operational and training use and have an identical manual of arms. When training with the .22 LR carbine, there is nothing new to learn. Like the .223, the .22’s bolt locks back after the last shot is fired. When a fresh magazine is inserted, the user hits the bolt release, just like the larger caliber version. Having identical manual of arms for both training and operations cannot be overemphasized. When operating under the stress of conducting an entry, or in a tactical operation with potential for “bad guys” to be returning fire, one’s duty weapon must function exactly the same as the training weapon because under stress, you will fight the way you have trained. If you must use a different manual of arms for training and operations, you may well be setting yourself up for some unpleasant surprises. With that in mind, let’s first look over CMMG’s .22 LR carbine.