Hallo there people!
Yesterday I've been on a trip with some friends, we headed East to the Umbria Region, following the path of the ancient Lombard, a Northern European population that invaded Italy during the VIth Century a.C. and founded a Duchy in the town of Spoleto.
Long story short, we visited 3 archaeological museums.
Many showed stuff from the Stone Age to Medieval times, and I found a Roman lead gland in one of them.
It was the Archeological Museum of Nocera Umbra, and this's the bullet:
 




 
Note that the plastic piece bearing the "11" number is only 1 centimeter (0.39 inches) wide  
It may be a votive gland, but I doubt it, as it woul be the only item with such a purpose in the whole Museum.
Greetings,
Mauro.

It appears to have a slight ding on one end.Possibly from use??

For an impact dent it is very gentle.Of course in case of hitting something soft it could be. As i remember it was found near a beach so impact in wet sand or shallow water could make such a dent.