In other discussions on this topic, the subject of flame temperature has been mentioned. I am not sure where one gets this information on various powders. Going back a long ways, double based powders that have nitroglycerine content, have been harder on barrels, I believe that this is because of their higher flame temperature. I don't have any specifics on 760, but 748 has been mentioned as having a lower flame temperature than other powders of similar burn rate. Having said all of that, there are other factors that come into this, such as pressure, which in a general way relates to velocity.