For the price of most military surplus, you can get a a modern bolt action with a warranty in a caliber that actually has large manufacturing support like .308, 30/06, .270 etc.. What used to be a cost effective way to get a hunting rifle, that shot decent enough ammunition to put down most game in Canada. Is now an expensive, gamble. Is the barrel still good? Is the stock got hair cracks? Does it even shoot well with all it's age and wear?
A quick look on the EE and I'm seeing them going for $1000 dollars and some of them look in piss poor shape. When I got into this sport about 4 years ago, I saw some for around $750. Even at that price I recognized that it wasn't worth spending the money on a rifle from two world wars ago, that may or may not shoot good in an old ammunition that is lacking industry support. When I can just go out and spend that money on literally any brands sub $1000 rifles. Like I can get a Mauser-18, savage Axis, Ruger American, or a Mossberg. The list is long.
Now that they aren't an economically viable choice for those looking to not spend too much money, they have no reason outside collecting a military surplus rifle or the love of history to be on the shopping list of new shooters. These popular military surplus platforms IMO only stayed popular due to their prices. They made them viable as cheap options that you gave to your kids or grand kids as a starter rifle. Or was cheap enough a young person could afford it. The ammunition was plentiful and cheap, the rifle cheap and available. Now that the .303 is lacking manufacturing support and expensive, and the Rifles are now expensive and hard to find. They will go the way of other surplus rifle types of the past, and be relegated to collector status.
I honestly see the market for worn out old military surplus rifles collapsing in Canada, and with it their prices. There will all ways be rare ones, and ones in great condition worth their money. But for the most part what modern hunter, or sports shooter is going to waste $1000 or more on rifles that get outperformed by $500 dollar guns. Both in terms of features but also group sizes.
On the topic of reloading and casting bullets. All my friends who hunt or sports shoot live in apartment buildings. Casting bullets in that environment is hard. Reloading anything right now is stupid expensive. Another reason people avoid old calibers that lack manufacturing support, as it's to pricey and time consuming to make their own, and it's to pricey to buy it off the shelf.