I made up three gallons of this, using 71B-1122.
The interesting thing this year is the berries seemed to be ultra sweet. I didn't even think to pull out my refractometer to check the berries' brix level, because I've made this wine many times and there seems to be very little variation in blackberries over the years.
This year, I used 5 pounds of sugar in the 3 gallon batch, and even without crushing the berries yet, I got 1.080!
Normally, I'd use 2 pounds per gallon, minimum, sometimes more! I expected to use 6.5 pounds total of sugar.
I left it at 1.080, thinking that I could add some more sugar with the topping up water if I wanted to boost the ABV a bit without making the wine too "hot". Right now, I'm on track for a just-under 12% wine so it may be exactly right. Blackberry wine can typically handle a higher ABV than some fruit wines, if it has enough berries in it. I'll sample at racking and decide then.