The Holland system pictured above is not a true "self opener", it is more accurately described as a assisted opener. Inside that tube is a coil spring of mediocre power, not really enough to spring open the gun like lets say a Purdey or Lancaster Model A who's systems are powered by massive V springs. When it comes to this Holland type system, if the gun is fired its works much less efficiently. The system also works much better if the barrels are long and heavy. Hollands quit calling this system a "self-opener" a few years ago, preferring to use the term "assisted opening". Just chiming in, didn't mean to go off topic.
Dustin
