I heard of that method (pun intended), but I never had any luck with it. maybe my hearing isn't good enough. I sort them right away. I figure space and $ tied up in post-1982 pennies could add up over time. It also gives me prompt access to other interesting coins in the roll. As for dumping the rejects: Have you thought about Coinstar? (no fee for gift cards, useful if they're for a place you shop at anyway) Also, some banks and credit unions have similar machines with none or lower fees I usually get customer-wrapped rolls and reuse those. When I get machine-rolled, I ask tellers for handfuls of paper rolls
Unlike silver, gold, etc., which is measured in troy weight, 31.1034768 grams per oz and 12 ounces to a troy pound, copper is measured in avoirdupois weight. One oz of copper is 28.3495231 grams and there are 16 ounces in a pound.