I want to build a rifle to drive the Matrix 165gr .277 bullets 3100-3200fps. I cant decide what brass to put behind this bullet to get the results I want. I am open to having a reamer made. I would like to use some combination of dies that are already out there like I do with my 7/300win using a redding s type bushing die. I would be open to having dies made or modified if I had to though.