Captchee, I'm an off-hand shooter/hunter myself,.... but as Mark says, any rifle/load that shoots terrible off the bench is going to shoot even worse off-hand.
First thing I do with a new rifle, is "bench it" at 100 yards, and if it's not shooting sub-2 inch groups at that distance then I start tweeking my loads.
After benching my rifle and working up the load it likes best, and "setting" my sights,... I know that any time I miss what I'm shooting at,... it's "my fault" and NOT my rifle or load.
I've seen guys that were pretty good off-hand shooters (on paper), but were terrible shooting from cross-sticks.
When they tried benching their rifles they found out WHY "that is".
I call it a "controlled flinch" which actually seems to help some people who "sight in" off-hand, and "shoot" strictly off-hand,... but might be as much as 18-20 inchs "off" dead-center at 100 yards when benched or shooting off cross-sticks. :shock:
Any rifle/load that is benched properly, will reveal any faults a "shooter/hunter" has, whether it's poor breathing, jerking the trigger, flinching, and etc. simply because any error with rifle, sights, and load, have been removed from the equation.
I had a friend in Alaska, that hunted moose with his Lyman GPR and lead conicals, and I thought the "rainbow trajectory" of his load was AWFUL, and it was,... compared to how it shot PRB's.
The last I knew, he still hadn't got a moose with his conical-loads and had went back to roundballs.
I also think, that with a gun/load shooting over-sized groups at 100 yards, pretty much eliminates taking an occasional grouse at 15-25 yards (with head-shots) when out hunting bigger game. (I used to do that, just so I'd be garuanteed to have something to eat at the end of the day.

)