Gareth,

Sorry to be pedantic, but the "greased" cartiridges didn't come in until the 1850s (in the British Army, not until the introduction of the 1853 Enfield rifled musket) - on the subject of the "grease", the only examples I have seen have been waxed, not greased.

The large calibe was more to do with black powder as a propellant than any hitting power and only became an issue after the introduction of rifling and breech loading for the majority of the Army (remember, on the general introduction of rifles, the calibre dropped from .75" to .577") (British military handguns, however, remained large calibre for just that reason).

Regards

Walrus