I am sort of ignorent of pre 1850 British weapons or any countries pre 1850 arms, so I speak in this post I am now writing with little authority, but I don't think that the muzzle loading Enfields or any of the PRE breech loading carbines had much use with the cavalry units. I am talking about the whole unit, officers and enlisted. You really can't successfully load a muzzle loader rifle or carbine mounted on a horse. What do you do, stop the horse and extract the ram rod and hope you don't drop it while loading or putting it back in the bands under the barrel? Between the sword only era and primitive breech loader era, a cavalry pistol was used. The Americans had one and so did the Europeans I do believe. The American muzzle loader was quite nice. It was a pistol with a long barrel, about 10 inches,(255 centimeters), and had a nice feature of a holster on the saddle. It also had a 'keeper' on the ramrod that was in the form of a swivel with a guide hole in it that allowed you to utilise the ramrod and then you could simply drop the ram rod and it would hang from the front of the pistol in the keeper with the bulb end pointing upwards to the sky and the bottom of the ramrod to the ground. You still needed to fumble with a small thimble shaped cap to press over the nipple. Many of these cavalry pistols had a 'Manyard' (?) tape system that replaced the need to put a cap on the nipple for ignition. It was a metallic(?) tape with small exlosive caps at intervals on the tape you could advance to fire, similar to the paper cap tapes used in childrens toy guns of the 1950's here in America. The gun was 'old school' in shape and form...one piece wood stock and handle, with metal lockplate and either a brass or metal cap on the end of the handle. I think it had a lanyard ring on the metal cap. Maybe not. It looked like a high tech classic 'pirate' gun fron an old illustration of the day. I saw one for sale a couple of months ago at a gun store...very pricey. I think between 3 or 4 thousand dollars. I am not sure, but I do believe that I saw several British and French 1840's era muzzle loaders with the same ram rod swivel keeper. Now wether the entire unit of cavalry was equiped with such a gun, or just officers, I do not know.
I think everything I have stated is true, but more needs to be said.