I have no idea where to find cast bullet data for Varget powder, but loading manuals written by jacketed bullet manufactures do a good job of keeping up with all the new powders as they become available. Jacketed data anc be used for cast.
Start with a listed bullet which is at least as heavier or heavier than your cast bullet. Try the starting load for jacketed and pressures will be safe if you are using LBT bullet lube and your cast bullet has a hardness of at least 20 bhn. If you are using another lube, you are on your own, my friend. Just buy good life insurance which covers accidental death, have your funeral arrangements made before trying your load, or your widow might use your photo as a target. I'm sorta partly joshing there, yet I'm dead searious about danger, as pressures can be double and more than they would be with LBT with most other lubes, including NRA Alox formula. Other lubes are worse. With mild loads lubrication isn't so critical but when pressures get up close to full rifle loads, lubrication quality and its abiblity to keep the bullet slipping under the high heat and pressure become absolutely critical.
