I got a 5/16" collet this morning at CDC to replace the one from the Bridgeport that was pretty messed up.
I saw your note. What was up w/ it?
When it wouldn’t go, the other Frank and I looked at it, polished it, and decided there must be a ding in the groove.
Someone at the space may also want to attempt to inspect the pin inside the spindle to see if it has taken any wear due to this collet.