RE: .303 British.
My first high power, back when they were available by mail! The rifle I got was pretty sharp... a late Canadian manufactured #4 with a 5 groove barrel and a nice brass butt plate. It had roughly hunter accuracy and I got fairly used to shooting various ranges with the big combat rear sight, just by adjusting my sight picture. This rifle was happiest with hard ball or round nose bullets. Pointed soft points would flatten in the magazine, but back then, Remington was putting out round noses in 215 grain and they managed better. Well, different cartridges do different things. I have great respect for the 303 and any cartridge like this that works. I eventually got a sporter stock, had a little work done and sold it off for a fair chunk of change. Looking back, I would have left it in original condition.