Any help / insight would be greatly appriciated. I was interested in converting my M3 into a NFA short barreled shotgun by professionally cuting the 19.75" factory barrel down to 14". I have searched all over the internet looking for pictures or forums explaining the process and I have only come up with airsoft conversions. My first question, is this legal if all of the ATF form 1 NFA steps are followed? My second question, will this adversly effect the function of the gun? Third question, recomendations on a good gunsmith that can cut the barrel and move the front ghost sight from its original location to the 14" barrel. Thanks in advance for your help.