All of the above is nonsense if you are using a ThunderBolt with 209 ignition. Blackhorn 209 is hands down the best in the ThunderBolt. BT209 is a smokeless powder of course, they say with a few additives but they won’t say what the additives are. It acts a lot like the 8400 that I experimented with way back when. It is not at all like the 5744 that I took to Africa. Be that as it may, it works like a charm in the T-Bolt, producing great velocities with 300 -450 grain saboted bullets. I have not yet tried it with heavy slip fit bullets