The gun: MG42 machine gun
The history: Nicknamed "Hitler's zipper" for the horrible tearing noise it made when fired, the German-built Maschinengewehr-42 was a belt-fed monster that entered service in 1942 and struck fear into the hearts of Allied troops everywhere. Prized as a trophy by Allied soldiers fortunate enough to survive it, the MG42 nonetheless had a fatal weakness; given its extremely high rate of fire, its barrel would overheat to dangerous levels and require replacement.
How it feels: Imagine staring into an open oven full of burnt fireworks and WD-40 while a burly guy shoves up hard against your shoulder, and you've got a rough idea of what shooting this thing is like. The MG42 is awkward to hold correctly; lying on your stomach, you'll need to grip the stock with your left hand while bracing it against your right shoulder. This is so you can raise the stock as high as possible, thus pointing the barrel - mounted on a folding bipod - downward and ensuring that your bullet spray doesn't arc up uselessly over your enemies' heads. It also emits a roar that's more deafening than any gun on this list except for the BAR, and the belt-fed shell casings it sprays out are hot enough to burn scars into unprotected skin. Which we learned firsthand when a few rolled underneath an editor's left arm.
In return for all this discomfort, this projectile meatgrinder spits out clouds of red-hot metal that will shred anyone or anything you put in front of it. Even firing it in short bursts, we felt an instant loss of control as the gun shuddered wildly, kicking up huge clouds on the big sand hill we were aiming at and sending bullets ricocheting off into a neighboring range that was being used by the LAPD. Thus we learned two important things: ricochets really do make that pnyowww noise in real life, and Los Angeles cops are remarkably calm about being accidentally shot at on shooting ranges.
Reality vs game: The MG42s we've seen in Airborne are either mounted on stable tripods or carried by extremely beefy German soldiers, either of which would have been a better way to experience them in real life. They're also much easier to control than the real thing was, and you'll be able to let off long streams of bullets that won't overheat the gun or make it jerk around spastically.
How well is it replicated? A few notches short of reality, but after sweating through what this thing can do in real life, we're not complaining.