Re: Half Stock vs. Full Stock
The fullstock rifles "look better" and more traditional. A drawback is if you pull the barrel to clean it, it's easy to break the barrel tang at the screw hole. Ask me how I know.
Halfstocks are more easily disassembled and cleaned. A drawback to most halfstocks is that they have a Nock (after Henry Nock)type breechplug. They sometimes don't fire quite as fast as traditional breeching, because it's a little farther from the touch hole to the main charge. It can be hard to clean down into the recess of the nock breechplug.
As for caliber, ya pays yer money and ya takes yer choice.