Training with missile weapons was done for centuries on butts (mounds of earth or soil) using a metal ring, or short of shooting galleries with a wooden shack against a black circle on a white background. Nothing like that prepares you to aim at a person with intent.
Overcoming that with targets shaped like potential enemies wasn’t done till the mid XX century. If you add to that the ability of soldiers to fuss and not being effective, or that unless goaded by officers, privates would rather do nothing or shoot in the general direction of the enemy to save face, up to WWII there was a lot of ineffective soldiering around.
Otherwise, it is very difficult to measure that sort of efficiency. Some weapons were very effective without having to be used, the flamethrower Churchill tank, for example, caused enemy bunkers and holed up squads to surrender without having to be fired. In the same way that a bayonet can be effective without needing to stab anybody.
If Western armies in the 50s saw that there was a problem, more than likely there was a problem.