I rebuild derelict rolling blocks. Does anyone know of an off the shelf group of components to make a good cartridge in .30? I have made one in 300 blackout on .357Mag cases but would like something different. I intend to use liners in 30 caliber, 10 twist with outside diameter of .370 so pressures need to be kept low! It would be ideal to be able to buy common dies to load the suggested round so cost would be kept down. Thanks for your thoughts.