I saved every '83 cent I received for many years. Didn't check the weight on them until I purchased an acceptable balance. So, about 2 years back, I dumped a shoebox full of ~2.5g 1983 Lincolns. I'll bet it could be something along those lines.
"Nummi rari mira sunt, si sumptus ferre potes." - Christophorus filius Scotiae