broadhead tuning

[speedster]

hi,
im pretty new to bow hunting etc and i hae struck a problem.
I have a martin Razor X compound set at 70lb,

Set up with 125 grain davies broadheads, my groups at 20m have left me puzzled.
they are grouping horizontally accross the target, never up and down , but side to side, quite often in a close to perfect horizontal line.
The bloke at the bow shop said to set the broadheads up as close to vertical when nocked as possible. Coul this be a problem.

any feedback would be appreciated

[jindydiver]

If it groups tightly with field points but the broadheads fan out like that you have got arrows with too light spine