Well a bit more of a close up would have been better. But damn that looks like a ball powder. Isn't 7828 a stick powder? 7828 is a very slow burn powder, even for a 300 WM. I not sure you could get enough of that powder in that case to create that kind of pressure.
After reviewing the load data in my Lyman 50th Ed. Manual it lists 74.5 as a compressed charge of powder and the max charge of 7828 for a 165/168gn projectile is 79.5gn. there is no way 7828 could have created that much pressure without some other type of issue, ie. An obstructed barrel. In my mind the powder you used in that load is largely suspect, if it were me in your situation I would destroy that powder. Maybe save a small sample if savage agrees to examine the rifle, and they ask for it.
After reviewing the load data in my Lyman 50th Ed. Manual it lists 74.5 as a compressed charge of powder and the max charge of 7828 for a 165/168gn projectile is 79.5gn. there is no way 7828 could have created that much pressure without some other type of issue, ie. An obstructed barrel. In my mind the powder you used in that load is largely suspect, if it were me in your situation I would destroy that powder. Maybe save a small sample if savage agrees to examine the rifle, and they ask for it.