My M&P 15 - 22 is probably my favorite "fun gun". Functions well, looks good and is cheap to keep fed. I put a Wilson Combat trigger kit in it to improve the pull -- nice addition, and was easy to do. I'm thinking of taking it to another level though -- getting it made into a short barreled rifle. Does anyone have experience in getting this done? I see that Innovative Arms does a slick looking integrally suppressed shorty conversion. If I send them my gun, do they have to engrave it, or is that my responsibilty with a Form 1? Thanks!