Been searching for a while and havent found a real answer. What length rail with A.R.M.S 41 B/L and Daniel Defense 18" mid barrel would I be able to go with. So far I have found the troy 9" seems to be the best option. Other option find a 8" rail so I can put the arms 41 and the end and not have problems of over lapping or just not fitting at all. Overall trying to do my own spin on a wanna be mk12 mod something. thanks in advance for the replies.