M-16 BUTT STOCK KIT This 1/2 lb. cleaning system replaces over 3 lbs. of conventional gear and fits into the stock of the weapon. With the flexible cleaning rod it is only possible to clean correctly, from breech to muzzle. The receiver, locking lugs, chamber, shoulder and neck can easily be cleaned. Bore obstructions, mud or snow, can be dislodged out the muzzle end. A stuck empty case or bullet lodged in the neck can be easily knocked out. NIW. These list on Otis site for $44. Sell for $15 shipped, USPS or any m.o. will do. I have 8 of these left.