Originally Posted by sniper42
Also, a 12gram stuck in the bottom tube is usually a tell-tale sign of a bad 12gram seal. When they go bad it pinches the 12ie and they get stuck.
Yep, this. When those seals go bad they tend to hold onto the 12g. Pretty easy to spot a bad one if they can take a pic down the lower tube. The only bad part is they'll need a valve tool to fix it.