It was the Lee Enfield Jungle Carbine (No5) and also the Winchester Model D that got me thinking about this.

This is probably a silly little question, but all of the big WWII long guns (Mosin, Springfield, Enfield etc) have wooden shrouding.handguards that go all the way up over the barrel, right to a few inches before the barrel ends. Given that the British seem to have had trouble sourcing a lot of wood at points during the second world war, I kind of figured this would be the first thing to go in order to expedite production? But you see it on every long gun and lots of the carbines of the time, even the last-ditch stuff.

What function does this serve and why is it not considered necessary on civilian/sporting/hunting rifles?

(Thanks in advance)