Looking at o/u, an autoloader was suggested for skeet

[cfullgraf]

The shell catcher that bearleft showed works well for singles when loaded as a single.

It can be swung out of the way for doubles. The gun will jam if it is not moved out of the way as the spent hull does not clear the ejection port.

 

[Jim Watson]

Somewhere in the clutter, I have a Morton Mechanical Shell Catcher.
It will save the singles and the second hull from doubles, so you need only drop 4 in a round of Skeet. A lot of mechanical magic and monkey motion.
A friend has the Morton Gas Shell Catcher on a gun, but it is a permanent modification. I had one of those but never installed it.
I don't think they are still in production, though.

The MultiCatch looks good, but I can't tell if they are actually still being made.