Lead for old 19th Century guns needs to be a little softer than modern guns so that low pressures will swell the bullet to fit the bore. Rotometals sells all kinds of lead, but has a 20 to 1 ingot that just fits the bill for an old '53 Enfield. Price per pound is only $2.59 US and even cheaper if you buy a lot. Some amounts even get free shipping. (and things don't get much heavier than lead.) Toll Free 1-800-779-1102.
Lead for old British bullets at Rotometals