I have enlarged pans with a Dremel, being a former power duck decoy carver I know my way around a Dremel.
Little diamond bits would be my choice for the job, the elcheapo ones cut like crazy but don't last long, I think I paid $5 for this set, there are several that are the perfect size to slot underlugs.
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My choice for the pan would be this one, it might take two of them to finish the job. I wouldn't dig a hole I would deepen the pan from stem to stern, of course I would take the lock out of the stock to do it.. This worn out bit is the one I use to touch up inletting, it barely cuts anything. Most people who let a Dremel get away from them and do damage have the wrong bit in it, or are trying to hog off wood.
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As for Dremels, I was once a tool snob, top of the line only, I had a variable speed Dremel and an expensive foot controlled Fordom. My first Dremel was American made and lasted 30 years with heavy use. When it gave up the ghost I bought a new one and noticed it was Chinese made, it lasted a couple of weeks.
I called the company and they said to send it back, "how much to fix it" I said, between "0" and $50 she said, "we have to see if it has a manufacturing defect or you broke it". A crap shoot, with $75 already invested I didn't want to chance dropping another $50 into it so off to Harbor Freight I went. I threw the Dremel in the trash.
$8 on sale, not as powerful Dremel but it works just fine, This one is on it's second year, if it burns up I think I can afford another $8 or $9 for a replacement.
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