Yes, it is equivalent, but just slightly different. To draw a bead on means to line up a shot, as in hunting with a firearm, such that the shooter has the target in the gun's sight. Note that one only uses a firearm's sight when one is taking one's time, lying in wait, making sure one can do the job with a single shot.
To have a good bead on thus means, figuratively, to have a good, clear shot lined up. It suggests the people so described see the target clearly and have command of the situation. All that remains for them to do is pull the trigger.