The advantages of rifle technology had been appreciated at least from the mid-17th century in Europe and, at the upper end of the arms market, hunting rifle-muskets and pistols became fairly common. The hunting rifle was extensively used by irregular and militia units in the American War of Independence and, indeed, earlier conflicts with Native Americans and the French (la longue carabine, etc.). There were, however, difficulties in adopting rifles for general military use. Doctrine at the time called for the “muskets” of a particular army to fire standard-sized lead spherical balls - understandable at least in logistical terms. This presented a problem for the rifle. Mass-fire smoothbore muskets could employ a fairly loose-fitting ball without undermining their effectiveness as short-range volley-fire weapons. Rifles, on the other hand, required the ball to fit tightly into the barrel, so that the rifling could grip the ball and impart spin. This was a difficult trick to bring off with spherical lead balls. The process of loading a “tight” ball was longer and more taxing than loading a smoothbore musket, and that was only the beginning of the problems. Spherical balls were highly prone to a phenomenon called “stripping” - whereby the spherical ball, rather than accepting spin in the grooved barrel, simply blasted itself straight out like a smoothbore ball - in which case it was likely to be even less effective than the smoothbore. Furthermore, the additional benefit of the rifle was pretty modest over the smoothbore and, to realize it, the rifleman had to have above average natural ability as a shooter, and had to have received elaborate training well beyond that afforded to the average, musket-bearing soldier of the line. Little progress had been made in addressing these problems by the time of the Napoleonic Wars. The problem of “stripping” had been alleviated to some extent in the Baker Rifle by enclosing the ball in fine wadding of chamois leather or some similar material - but it was not an advance sufficient to allow the rifle to be adopted as the rule in military musketry. Its use, while common, was confined to sharpshooters and specialist “Green Jacket” units. The same, I think, was true of the armies of Britain’s German allies.
The advent of rifles as a general feature of military musketry awaited the development, in the 1830s/'40s, of a new form of projectile - the "Minié Ball - which was designed fit relatively loosely on loading but, on firing, to deform and “spread” into the grooves of the rifle, allowing spin to be imparted with little risk of “stripping”. The new “Minié Rifle” remained difficult to fire with any accuracy - this was a feature of all low-muzzle velocity black powder rifles through the relatively short period of their predominance. However, they did prove to have superior effective range, even if this was not always best utilized by inadequately trained or inexperienced troops. The Minié Rifle, and its immediate descendants, were still used primarily for volley fire (although this, to be fair, was partly a matter of the conservative military mind). Nonetheless, it had a profound influence on the fighting of wars in the mid-19th century, principally the Crimea War (in which British units were extensively armed with Minié and Minié-type Enfield muzzle loaders) and the American Civil War (the only war in which muzzle-loading rifles predominated in the front line on both sides). Then, of course, things moved on … Best regards, JR.
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