Nothing serious, Mac. After thousands of rounds, the transfer bar crystalized and broke. Replacement was about $12, but it took me some time to get it and some more time to get around to putting it in. It's fixed now, and if the weather clears this afternoon, I'll shoot and post a "what might have been" card.
This is the first part I've had to replace in something over 15 years, and I've used this rifle the way normal folks use a .22 plinker, so it's been shot hard.