I'm going to tell on myself about something that can cause ftfeeds. Take the mag apart to service it. When done re-install follower.....upside down.
Then at the range discover what the problem is, take the base plate off of mag. Have spring propel the little latch part out into the 6" grass in front of bench. Look for said part until convinced that a snake ate it and it's gone forever.
However, now that the follower is in correctly, mag performs fine. Black Gorilla tape works well until said missing part is located and purchased.
Moral of the story: A snake in the grass can be a pain in the...