A CQBR replaces the upper receiver with each barrel to make it a short barrel of 10.3 inches to make the M4 compatible with close-quarters combat (CQB = Close Quarter Battle) in a narrow room. Of the three versions of CQBR, the model called “Block1” is available in his gas blowback machine gun!
By installing new mechanisms such as the Z system developed for the M4A1 MWS, we pursued the reality of shape and texture while achieving both high durability and operating performance. In addition, the scalability for optional parts has been enhanced, making it easy to handle even in narrow spaces.