Venezualian Mauser

The same general rule applies. The largest diameter cast bullet that will easily chamber in your rifle will have the highest accuracy potential. Simply apply ink to the exposed driving bands on a dummy load. If the ink is not marked on the bands from chamber/Un-chamber of your dummy round, your cast bullets are not big enough to shoot well. Use the  largest diameter cast bullet that will function and you will have the best fit for accuracy potential. Just do what you have to do to get the fit. You may have to hone your bullet mold and/or your bullet sizing die to get a sliding fit upon chambering. Then you will have the most accuracy potential to begin testing loads. A moderate hunting load level will need  BHN15 Lyman #2 alloy or similar for the load pressure. Cast Bullets that show sliding contact in ink upon chambering indicate the bullet will have a stable start for firing regardless of LOA or ball seat. No contact and the bullets will start wobbling down the bore upon firing and shoot poorly below the accuracy potential of a cast bullet that fits and checks correctly with the ink test.. Gary