I know there is a weight tolerance to the 3.11 but I believe this is a bit outside of it.. It’s not any thicker than a regular 1953 and it’s not magnetic. Any thoughts? Is this simply an extra thick planchet?
Assuming there is nothing on the reverse to account for the weight, like some foreign substance, then a slightly thick planchet is about the only answer.
The tolerance range for copper Lincoln cents is 3.11 grams +/- 0.13 gms, so any thing between 2.98 and 3.24 gms is normal. Assuming your scale is accurate, your coin is slightly over weight by 0.08 gms. As @l.cutler posted, it was likely struck on slightly thicker planchet. At only 0.08 gms over, you probably aren't going to notice a thickness change due to process variations with die set up distances and striking pressures. Technically, it would be a be an error, but at only 0.08 gms over, it's unlikely there would be any premium attached to it
