Del - since we dont know what weight is your "regular" arrow for field shooting we cannot make any assumptions, but if it is built on 11/32" shaft, it wont be likelly over 500 grain.
To enlighten you, this guy claims to shoot an arrow, which is heavier than BLBS Standard (60 gram - more like livery) 250 yards with a bow of 75#. Minute look at results of batsford flight shot and "Standard" shows that only 4 people, arguably of the best english heavy archers shot that distance with bow 130# and 140# respectivelly. Even though I would gladly cut him some slack for less fletch on his arrows than standard prescribes, one doesnt need to be bloodhound to smell bullshit.
He is basically claiming that his 75# bow is shooting 185-190 fps with 13 grain/pound, I hope you can see the nonsense.
Having seen shoot some of the better longbowmen at hand, with bows of this weight in very good yew bests of Boyton made I can safelly claim that the bow is either not 75# or his arrow is at least one third lighter than he claims (and even so 250 yards will be rather nice) or they didnt measured the distance correctly.
J.