Just another SWAG !!!
13 v 17 anybody? I certainly don't know
In the early years, I used TC-13, and have not taken the opportunity work with #17. Seems to me that it might be addressing the use of Sabots. In recent years I have switched to a 50/50 mixture of Balistol and Mineral Spirts. So, for now, that is what I'm stuck on. There are many positives to Ballitol and the only negative may be, the smell. ......
Back in the 80's when I started using #13, there was only BP and Pyrodex soon followed. There were a number of BP solvents that were basically the same. You could tell by the smell of Murphy's oil soap. Most were very effective in working with Sulphur based propellants. Today there are many alternative propellants and I have to think that #17 addresses those as well .....
Be Safe !!!