Hodgdon's max is 63.5 gr of Retumbo I have been able to work up to that with both the 140 gr Accubond and Partition can't see why you couldn't work up the 140 gr SST. Magnum is another powder that works well for some guys Ramshot's max is 65.3 gr. I worked up to 65 gr with both Nosler's but didn't get the accuracy that Retumbo gives me but your gun may.
Just noticed Ramshot says you can go up to 68.3 gr of Magnum with the 140 gr Hornady A Max.
Last edited by gerrygoat; 02/04/12.
