Here's my issue:
I have a 2 year old meticulously maintained M2 field lefty 12 with maybe 1500 rounds through it. Last week while shooting doubles the 2nd shell was not being grabbed from out of the magazine tube. Had 3 failures in the round of 50. Took it home, cleaned it and fired 100 rounds 3 at a time flawlessly. Nothing new same shells. Used Rios, Federals, and Nobels. Any ideas?