I have one for my AR15. Its very handy for normal cleaning, but if you get a squib load, or a round that wont extract, you're almost SOL. Since there is no full-length rod, I end up dropping the short 8" rod that comes with the kit (to clean the chamber on an AR15) down the bore from the muzzle, hoping to dislodge the stuck object by the impact. Obviously, thats not very good for the barrel, and should be avoided if possible. The Otis kit is good, but keep a solid cleaning rod with your shooting gear so your range day wont be cut short by a stuck casing.
Kharn