I know pop used to use black powder 22lr as it was cheap, but I couldn't guess as to what version of extra long it took.

Versatile one rifle calibres have a big place in history be it something like that 22lr, the aforementioned 25/20 or especially something like the 303.

I like a lot of the "officer" model Lee Enfield rifles in 303, they weren't just a weapon of war but something the gentleman could use to hunt with whilst away on duty.
I think they have as important a place in sporting history as the civilians Lee speed in many ways.
They definitely have accounted for a lot of game in the colonial days.

I think that's why I also love the 9.3x62, as I mentioned earlier on many people could only afford one gun back in those days and the 9.3x62 proved perfect for putting meat on the table, killing destructive big cats and could even be used on the occasional rampaging elephant.
These jack of all trade rounds seem to have lost favour these days as people tend to own a battery of rifles for all occasions.

I think a Lee speed style full would carbine would be the rifle I would have chosen if I was in that situation way back then.
But a lot of the 303 sporterised and custom built guns here in Australia are our version of the Lee speed in concept in design if not always in beauty.