A hailstorm of bullets?
Hardly.
Best guesstimates point at 4-6 shots, all aimed at the limousine.
Let's assume your theory is correct (it isn't, as I will demonstrate), using the conspiracy buffs' favorite alleged shooting sites. For a "triangulated crossfire," everyone's capping off at least three shots (anyone who was in the Army, like me, knows this). Try a minimum of 9 bullets, more likely 12-16. We've accounted for four of them. Where'd the rest go?
Well, as any law enforcement officer (again, like me) knows, they would've gone into the backstop.
Said backstop, in this case, being the crowds of people on each sidewalk.
How come nobody but Kennedy and Connally got hit? Did they use special bullets that, if they miss their intended target, just disappear in a puff of illogic?