What does "coming along really well " mean ? Have you picked any toms at all ?
Brandywines do have a longer DTM (days to maturity)
And the hotter weather surely has been probmatic for many.
Just hang in there/

Check out the FAQs list here (direct linked on the forum page). Your question is a common one and you'll gain a lot of info there by reading about about Blossom Drop. Plus as already mentioned, Brandywine is a late season variety. And if you search 'flowers but no fruit' in this forum you'll find many in the same boat.

All this not to mention the unusual weather in most all of the country this year.

Dave

never did have any great success with Brandywine so gave up

I have read and heard from multiple sources that tomatoes pollinate best when nights are cool and days are hot. It certainly does seem like the gardeners who have good-sized tomatoes in early spring get more tomatoes than I do with my Mother's Day tomato plants.

If you have blooms and no tomatoes, take out an electric toothbrush and give the plants some shake (or shake them by hand) to encourage pollination. This method seems to work for me.

Well my Tomatoes (2 Better Bush) are both basically dead at this point, I got around 150-175 tomatoes between the two plants. Planted them in early April and they are done and dead in mid August, produced about 75-85 tomatoes per plant.

They are Determinate plants though.

Now I planted 3 Dwarfs which are indeterminate that were basically planted first week of June.
The HEAT and HUMIDITY have taken their toll on them.
The plants are fighting off Blight and are dropping on average 2-3 blossoms per day.
I only have just 3 tomatoes set on one plant.
But up until the past couple of days the temps have been in the mid 90s to low 100s and even at night it has been close to 80.

Next year I am going to plant them as early as possible, probably in March in the Vegtrug under the greenhouse cover then transplant them in their growing pots when they get too large (22+") for the Vegtrug.

next year it could be cold and rainy just like this minute which brings on a whole bunch of new problems