At first I thought this may simply be due to lack of water when it was needed, I noticed some fruits ie black berries had completely shrivelled this year where there was lack of ground water.
What I hope its not is Pyracantha scab, this can be identified by blemishes on the berries in the form of scabs, this is similar to Apple scab and can be sprayed, if the berries hav become small and blackened, I would think it has become severe and may be worth destroying the bushes and starting again. There are a couple of resistant varieties such as 'Shawnee' and 'Teton'
I hope my first thoughts were correct rather than the latter!
Good Luck Tbird+