In September, 1977, on a chamois stalk, a jaegermeister (professional hunter) from Carinthia climbed to the top of "Kometeralpe", a 2,500-meter picturesque mountain. After shooting a chamois with his Mannlicher Luxus 6.5x57 topped with a Kahles Helia 6x42 riflescope, the jaegermeister rested his firearm against a boulder and ascended to where the game was taken. After field dressing his animal, he returned to the spot where he believed his rifle to be. Unfortunately, the hunter spent the entire afternoon searching the mountainside for his gear but didn't find it. In the ensuing days and weeks, he regularly returned to the area to search for his rifle but was unsuccessful.
Months, years, and a quarter century passed. High above the timberline, rifle and scope rested upright against the boulder -- being abused by the harsh elements of nature at this high elevation. Summer heat and dust, followed by strong storms and heavy showers of ice and snow tested its durability.
Almost three decades later, Hannes, a young jaegermeister from Obervellach, a small village in the Austrian Alps, ascended the same mountain, stalking a chamois. After making a good shot, Hannes proceeded down the slope to his animal.
To his amazement, next to the chamois and just barely visible, leaning against a gray stone boulder, was an old rifle. The stock was rotten and bleached by the elements, and all of the steel parts were rusted throughout -- a sad resemblance of what once was a hunter's pride.
The rifle was in poor, unusable condition, but when Hannes looked through the scope he couldn't believe his eyes: the image quality was like that of his new modern scope, with the crosshair standing out crisp and clear against a sharp, brilliant and extremely bright image. The steel surfaces were rusty, yet all of the aluminum parts were unharmed. The mechanical parts, including both elevation and windage adjustments still worked perfectly, and even after all those years in the most extreme of elements, the scope remained waterproof.
Interesting side note: the Unertl company, which also makes scopes, was founded by John Unertl Sr., who immigrated to America after serving as a German sniper in the First World War. I don't know what background questions they ask on application for citizenship these days, but the story is that back then one of the background questions was "Have you ever killed anyone?"
Unertl's answer was: "Two hundred forty-seven Bulgarians."