This is pretty dang cool but I just recieved my Grandpa's relaoding research and data for the rifle he gave me. Has about 15 different loads, all with velocities, pressure notes, group sizes. Talk about a cool gift! Gave me everything I needed to start doing my own loads for it. He had 4 loads with 1/2 MOA groups or less. Kind of crazy with this wood stocked hunting rifle built in the 70's on a Mauser action. All of his loads were with H4831 with Hornady 100gr or Sierra 129gr projectiles and I was wondering if I can sub IMR4831 or H4831sc in its place and start a grain or 2 low and work to his measurements.