by AS30N » 30 Oct 2023, 7:03 pm
As above, you need to try and stick a cast boolit into the case mount of brass fired in your gun. If it fits, try around 10 gr of TB with the 312 boolits.
As for 2206 H, I am not sure if you can get it slow enough to work. Even if you do, you will do gas checks. Beyond 1400, or some say 1600 ft/S with extremely hard lead alloy and heavy coating, you will need gas checks, period. Cheapest way is to get a Lee sizing die in 308 (strongly recommend you hone it to 309), it will size and seat the gas check at the same time. Personally I will use 2207, it's fast burning enough to keep the velocity below 2000pfs (even with gas check it gets difficult to get a good group beyond that point, not too mention excessive leading.