Crossbows have a very short power stroke, so the draw weight must be much higher that for a conventional bow to get adequate killing power. Generally 150# or above is reccomended. Penetration is strongly affected by the total weight of the bolt & broadhead, as well. For that reason, I prefer cardon crossbow bolts.
There are times when the deer are simply not moving and you're forced to make something happen. Maybe you're up against a full moon or hot weather. This is when a silent drive to force deer to move should be considered.
By silent drive, you're not yelling and making a commotion to scare the deer. When deer are panicked, they're liable to bust out of the cover on a dead run, and any shot you get will be tough to make.
A silent drive is different. It means playing the wind to carry the driver's...