Hi Rich,
Listen to Nick. Most rods were 2 pieces including the button headed ones. Iron rods were used early in the 18th century but militaries quickly upgraded to steel despite the extra cost. The iron rods bent too easily. Here is an exact description of how they were proofed in the early 19th century written by John Marshall, clerk and paymaster of the Ordnance in Birmingham:
" The Ramrods were proved by putting the end on the ground and taking the head in the hand and pressing upon it, and bending it in various directions; if after this proof it continued straight, it was taken hold of in the middle by one hand and held vertically the head downwards, at a considerable distance above an anvil and allowed to fall upon its head, in order to make it ring, and to ascertain if it was sound, if it resisted these proofs, it was marked under the head and received into store."
Are you making a COS musket?
dave