2015-D 1 Cent Bubbly

doesn't look to be affected by heat

Just curious can you weigh it?

Nope they're supposed to weigh 2.5 so nothing strange about the weight.

See the discoloration at the top of the reverse? If I had to guess, I'd say that's where the coin was pinched by a pair of pliers, to hold it in a hot oven. I think the distorted shape is just due to the zinc core melting and making the copper foil look lumpy.

A while ago I would melt zincolns for fun and sometimes they'd turn out with bubbly copper foil like this one, albeit with much more oxidation that occurs at a high rate on the hot copper surface. Maybe the coin had some oil or something on the surface that passivated the surface so it didn't oxidize in the heat.

If this were a late stage die cap, I'd expect less detail and/or less bumpiness of the copper foil.

I agree with heated.

But pliers grab, why is there no mark on the observe side?

There is a mark on the obverse at 6 oclock-its lighter in color but if you enlarge it you can see its there

You mentioned it came from a new roll. Was that directly from the mint or a bank?

I meant 2015