I WANT TO BUILD A A SEMI CUSTOM 300 WIN MAG. MY QUESTION IS WHAT ACTION TO USE. DO I BUILD IT OFF A REMINGTON, SAVAGE, OR RUGER FRAME. ALSO DO I GO OUT AND BUY A NEW RIFLE OR FIND ONE USED. HERE IS WHAT I WANT, A STAINLESS ACTION AND BARREL WITH A THUMBHOLE STOCK WITH THE RIGHT GUNSMITHING AND OPTICS TO BE A COMFORTABLE 50O YARD HUNTING RIFLE. ALSO DO I GO WITH OR WITHOUT A MUZZLEBREAK?