I have a cuple of fluted barrels from bolt actions that I may try to use. I dont think there are any accuracy gains from fluting a barrel..Possably it might not get as hat as fast and walk less but Im sceptical. weight saving and looks are thae main reason people go that route. ill likely go with a AMD lengt or standard pistion . i dont see any advantages to going with a short pistion unless the GB location some worked as barrel tunner in certain area. (hmmm may build it with no port and slide the gb up and down testing it with out gas )
I started a thread oin doing a swithc barrel buld a year or so ago. Its on hold untill I get caught up with a few things around here. I have about a dozen caliburs in mind. and the barrels in hand. I got a m70 trunion bored out to take a thread that is avaliable in a common tap size. and it kind of ended there.