Much of shooting live wasn't to teach marksmanship, but was battle innoculation. That said, the British were taught a much more effective musketry practice, they were taught to aim (straight down the barrel using the bayonet lug as a sight), release the shot properly and only fire at 100 yards. This enabled them to get the first few volleys on target, doing great execution, after a couple of volleys there is enough smoke that the accuracy of shooting drops tremendously and being better shots doesn't really matter.
The British of the Napoleonic wars relied heavily on the bayonet. The French were happy to stand and shoot all day, but level bayonets and give them a charge and they'd break before bayonets were even crossed. The same is true of a lot of low quality forces.
Napoleon's Army of England he built from 1802-5 was beautiful, some of it's Corps were easily the best troops in Europe (there was huge variation, depending on the quality of the Marshal), but he spent them in 1805-7 and never really had high quality troops after this.