I found this overweight 1978 penny and can find no info on it, seem thicker than normal. I posted a side view photo next to a 1980 penny. Anybody see this before???
Yes. It's a Cent struck on Thick Planchet. There are instances where the sheet of metal was not properly made into the required thickness. Sometimes it is even made thinner than normal.
There is a mint site though that gives all the weights and tolerance someone my know it good luck Heads up
Tolerance for a copper cent is .13 so your cent is a bit overweight. 3.1 + .13 = 3.23 would be within tolerance Your coin is .31 of a gram overweight, if your scale is accurate; more than official tolerance, but not significantly overweight.