[Toschano]

It sounds more like it might be hanging up under the extractor and not fully seating leaving it at a bad angle to enter the chamber.

 

[Toschano]

Take a stone, not a Dremel grinder but a fine hand slip, to it and smooth it out a little at a time until you have a positive feed. Using a dummy round, behind the extractor...it shouldn't be a loose fit but snug. Since it isn't doing it all the time, polishing it with Flitz, or for that matter, fine dental tooth polish might suffice. (You can use the Dremel to polish. LOL)