Maintain your AR-15, M16, M4, and AR-10 rifles in optimal condition by using these Original military-style design 5.56 NATO .223 caliber Chamber Brushes. These brushes are specifically designed to fit the chambers of AR-15, M16, and M4 rifles, as well as the larger .308 chamber found in AR-10 rifles. The .223 bronze bristles effectively clean the rifle chamber, while the longer stainless steel tufts target and clean the locking lug recesses. These brushes can be directly threaded into any standard cleaning rod with an 8-32 thread. The AR Rifle Chamber Brush set includes three brushes for 5.56mm/.223 caliber rifles.