Good thought, but nope, checked that; base pin and plunger are operating normally. It catches way before the transfer bar starts to move significantly, just as I start to thumb back. Can't see too much inside the action to see what's catching 'cause the hammer isn't pulled back very far, but almost feels like a metal bur somewhere, nothing external I can see. Bolt doesn't look like it's hanging up on anything. Haven't completely dissassembled to look, but that might be next...