The method you seem to currently be using is 39 bytes:

`>>+++[<-[-<.>]>-]++++[<----->-]<-[-<.>]` (not including getting the `A`) ([Try It Online!](https://tio.run/##SypKzMxLK03O/v9fx85OW1s72kY3WtdGzy7WTjdWG8IHASAPJvH/vyMA))

(loop 3 times, each time set the counter to 255 and print that many times, then subtract 20, subtract 1, and print that many times)

However, it is much shorter to loop 4 times and print 250 times each time:

`>>++++[<------[<.>-]>-]` (23 bytes).

If your cells are unbounded (I'm assuming they're 8-bit otherwise you probably wouldn't try using 255 for golfing):

`>>++++++++++[<++++++++++[<..........>-]>-]` (42 bytes).