It is quite stable as far as far as I can tell. In the 243Win I tried it from 59-93F using the fast charges used shooting 100 gr bullets and saw <10 fps difference in speed at the higher temperatures with no signs of excessive pressure developing. It also is potentially useful in a lot of cartridges. I was looking through several old Hodgdon Annual Manuals and every cartridge that is able to use H100v can potentially use StaBall since SB is a little slower burning than H100v. I have recently found that you can use 1-2 gr more SB for the same bullet than was specified for H100v. I always start at the lower charge range first and work up to guard against some idiosyncratic behavior.