I have enjoyed reading many of the posts made here so far. I own a .44 carbine (scoped) and consider it a great carry rifle, plus being an excellent choice for whitetail or even black bear to 100yds or a bit more, with proper ammo. Some of the posts about larger game do give me pause though, and my opinion would be that any thin-skinned game is in grave danger at muzzle to 100+yds or so, if shooting good bullets (an example would be a 270gr Speer Gold Dot SP, not HP ammo).
I'd think a .44 would likely kill an elk at 100yds with such ammo on a broadside shot, no doubt, but not immediately(DIT) unless the neck or vertabra were hit. The power of the .44, even in a carbine with it's much higher velocity does, in my opinion, dwindle quickly when game size or type increases. I've seen several comments on wild boar, and it's good performance on them. I'll agree, but only to a point. But a boar of over 250lbs is a pretty tough animal and with it's vitals well protectected by it's thick protective shield of cartiledge is another deal, in my opinion.
Not trying to P*e in anyone's cornflakes here, simply not wanting anyone undergunned and possibly facing danger due to that. I love my Marlin .44 and it's a potent and handy gun, simply not an elephant slayer, grizzly gun nor the safest thing to shoot a close range LARGE wild male boar with. Again, simply my opinion.