These sorts of circular scourings - often called the "
Ring of Death" by collectors - have various causes, but all those causes are
PMD. Those coin-roll-crimping machines are one such cause; getting caught in a
Gumball Machine, slot machine or some similar mechanism is another. Sometimes, it's simply someone who has said "I wonder what happens if I switch on my electric drill buffing brush and slam it down onto a coin", and found out the hard way exactly what happens.
On this forum, we do prefer it if you restrict your posts to "one coin per thread", unless the coins have similar features or otherwise linked; you're more likely to get fresh eyes onto each coin if you do that. If that means you're posting 20 different threads per day, so be it - we actually prefer it that way, to dumping all your coins into just a couple of threads.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis