The flame spitters used to have different stats. The HSR used to be 15% but was changed to 10% when Nightfall released. I'm fairly certain these were all retroactively changed, unfortunately, kinda like 20% HSR rockmolders. The 10% ones are still obtainable.
That said though, check out the prenerf subforum for other info on things like this. Your storm bow falls into this category as well. *cough* check your greens *cough*
Changed the title of the thread from “PC req 8 Stormbow & HSR 10 flame splitter of enchanting” to “PC req 8 Stormbow & HSR 10 flame splitter of enchanting close”.