I have the 250 in a standard barrel and have found that the Hornady 55 gr. flat base shoot better in it by about 1/2" @ 100 , the BKs were running at right 1 1/4" @100 . my 223 bull barrel on the other hand just loves BT bullets .
The best thing i can tell you is to try both and see which kind it likes best .
stimpy