I have a 1863 Indian penny that weighs 4.1 grams
Post a picture of it on a scale
Could be lot of things. Corrosion, damage, scale set up or calibration, scale operator error, thin planchet, something else?
Need focused, cropped pics of the coin. Seeing a small coin with lots of background, or fuzzy images doesn't help
BTW weight standard for an 1863 cent is 4.67 grams, not the 3.11 grams that started with the composition change in 1864, in case anybody was wondering
Nickel is to show that my scales are accurate....
Looks to be acid treated
Yeah I know the weight is suppose to be 4.67 grams...With that being said .5 grams is a lot and the penny does not have that much damage
The cent has a lot of corrosion/environmental damage. With that much damage, it would be nearly impossible to determine if there is actually something else going on. The most likely cause of the weight loss is the obvious corrosion. Saying "it doesn't look like that much damage" isn't very useful data to claim it was an underweight planchet or some other error.
To paraphrase the 14th century Franciscan Monk and philosopher William of Ockham - the simplest explanation is usually the best explanation.
The loss of weight is from corrosion.
Heavily corroded and wire brushed is my guess.
P.S. - Your good pics make it easier to diagnose.