yeah I would have thought given the original serial number/gun was a cat H it would stay that way. Unless it was "remanufactured" into a new gun with re-issued serial number etc.
yeah mate get the tried and tested and venerable 10/22, we had two when I was a kid, they're great, wish the old man had kept them, but alas I was too young to go through the rigmarole to get them.
The few clubs that allow Ruger Chargers for Metallic Silhouette generally don't allow pistols in chassis or shoulder braces even for practice, pistol Metallic Silhouette competitions certainly don't and there's nothing else that the firearm is approved for. I would suggest checking with your club first, as it's a Cat H pistol there won't be anywhere else that you can use it.
People who are serious about Met Sil don't tend to use semi auto pistols so it won't be competitive compared to a single load pistol like the Thompson Contender, although it would be more fun to use.
Just like our laws are ridiculous the chassis doesn't change the category but it makes it look scary so most clubs have banned it outright based on appearance. It's not worth it if you live outside of Qld.