It's always nice to find targets like that: good signal and fairly old. I agree the cylindrical bullet with the rifling marks is from a factory load, probably late 1800s or early 1900s. The lead ball is likely from a muzzleloading gun, a musket,pistol or rifle.
We have a military establishment here which dates to the late 1700s and was occupied with militia until the late 1800s. I've found many different calibres of bullets around the area and speculate that the soldiers went out and did recreational shooting of their non-issue weapons. That may be what your finds are.