I just got back from shooting my m&p 15 for the first time. I love it I used a combo of American eagle 55 grain fmj and tcw 56 grain fmj steel case ammo. It cycled perfectly not one ftf, or jam no problems at all. Very accurate even my wife loves it. Now I need to clean it anybody have an opinion on what to clean it with. This is my first gas operated gun and I don't won't to use what I have to clean it.