The bottom barrel is not firing. What can cause this?
Dies it sound like a light strike? Weak spring broken firing pin.
It still strikes but not hard enough to fire. I am ordering firing pins and springs for both barrels.
Lots of things. Broken firing pin, broken/weak hammer spring, dirt or debris in action, deep set primers and a few others. My 525 has been flawless these past 15 years or so but by saying this I have probably just put a hex on it.
First thing I would do is hang it action down and spray it out with a gun cleaner, being careful not to get it on the wood. If that doesn't help you'll have to remove the buttstock and check for the other problems. If you aren't comfortable with doing that, take it to a gunsmith or send it to Browning. Of those 2 alternatives, I personally would send mine to Browning. Bob
Does it make a difference where the selector is? Most likely a broken firing pin and/or spring. Citori's are known for having firing problems with the bottom barrels, due to the angle of the pins/springs in relation to the hammer angle. It's not real common, but the most common failure in most Citori models.
Try different shells