Here's a couple of .69 calibre minie balls that I found at a Vicksburg campaign site that were hard rammed down the musket barrel during the fight.
Black powder musket barrels fouled easily and the more it was fired, the more difficult it was to ram the bullet home, leaving a deep distinct ramrod impression in the tip of the soft lead bullet. You can only imagine the soldier putting his shoulder into ramming the bullet down the barrel in the heat of a fight and probably mumbling a few choice profane words in the process.
These type of minie balls are fun to find and tell a story about the use of small arms as a battle progressed.
Another example from the same battlefield. This one is a .58 minie.