Barnett lists that crossbow as coming with 2 each 20" arrows.
Normally these arrows can weigh 400 to 410 grain including a 100 grain point.
To get that speed providing the crossbow is properly tuned, Barnett normally uses
a 380 grain arrow-point combination, but does not recommend shooting that weight.
Where Barnett defeated them selves is building a narrow crossbow which is good in
a tree stand or blind. Building the bow with a narrower riser and shorter limbs reduces
the speed that one could obtain from a wider riser and longer limbs.