OP - I have no clue if Wikipedia is correct or not - I found this about the early Russian production - from that article, there were a number of variants made earlier than M43, so not real certain what you mean by "original". SKS was basically a Russian invention, so "original", I suppose, would be what they used??
"The original Soviet M43 bullets are 123 grain boat-tail bullets with a copper-plated steel jacket, a large steel core, and some lead between the core and the jacket. The cartridge itself consisted of a Berdan-primed, highly tapered (usually steel) case which seats the bullet and contains the powder charge. ..."