incredible but hardly impossible
here are two other amazing snipers from earlier this century
a Finnish sniper operating during the Winter War between Finland and Russia just before WWII, had over five hundred confirmed kills using iron sights.
The unofficial Finnish frontline figure from the battlefield of Kollaa places the number of Häyhäs sniper kills at 542. A daily account of the kills at Kollaa was conducted for the Finnish snipers. Häyhä used a Finnish variant, M28, of the Soviet Mosin-Nagant rifle (known as Pystykorva rifle), because it suited his small frame (5 ft/1.52 m). He preferred to use iron sights rather than telescopic sights to present a smaller target (the sniper must raise their head higher when using telescopic sights) and aid concealment (sun reflecting off telescopic sight lenses can reveal a snipers position).
Besides his sniper kills, Simo Häyhä was also credited with as many as two hundred kills with a Suomi M-31 SMG submachine gun, thus bringing his credited kills to at least 705. However, the latter claim has never been substantiated. All of Häyhäs kills were accomplished within 100 days prior to injuries caused by an enemy bullet. Häyhäs record of an average of 5 kills a day, almost one kill per daylight hour of the short winter day, is unique.
5 kills a day with ironsight, thats just crazy
Lyudmila Mikhailivna Pavlichenko
(Ukrainian: Людмила Михайлівна Павліченко, Russian: Людмила Михайловна Павличенко) (July 12, 1916 October 10, 1974) was a Ukrainian Soviet sniper during World War II, credited with 309 kills
Born in Bila Tserkva on July 12, 1916, Pavlichenko moved to Kiev with her family at the age of fourteen. There she joined a shooting club and developed into a sharpshooter, while working as a grinder at the Kiev Arsenal factory.
 World War II
In June of 1941, 24-year old Pavlichenko was studying history at the Kiev University when Nazi Germany began its invasion of the Soviet Union.
Pavlichenko was among the first round of volunteers at the recruiting office, where she requested to join the infantry and subsequently she was assigned to the Red Army's 25th Infantry Division.
There she became one of 2,000 female snipers in the Red Army, of whom only about 500 ultimately survived the war. As a sniper, she made her first two kills near Belyayevka, using a Mosin-Nagant bolt action rifle with a P.E. 4-power scope.
1943 postage stampPvt. Pavlichenko fought for about two and a half months near Odessa, where she recorded 187 kills. When the Germans gained control of Odessa, her unit was pulled to be sent to Sevastopol on the Crimean Peninsula. In May 1942, Lieutenant Pavlichenko was cited by the Southern Army Council for killing 257 German soldiers. Her total confirmed kills during World War II was 309, including 36 enemy snipers. In June 1942, Pavlichenko was wounded by mortar fire. Because of her growing status, she was pulled from combat less than a month after recovering from her wound.
Pavlichenko greeting USMC Donald AldrichShe was sent to Canada and the United States for a publicity visit and became the first Soviet citizen to be received by a U.S. President when Franklin Roosevelt welcomed her at the White House. Later, Pavlichenko was invited by Eleanor Roosevelt to tour America relating her experiences. She appeared before the International Student Assembly being held in Washington, D.C., and later attended CIO meetings and made appearances and speeches in New York City. The United States gave her a Colt automatic pistol, and in Canada, she was presented with a sighted Winchester rifle, the latter of which is now on display at the Central Museum of the Armed Forces in Moscow. While visiting in Canada along with Vladimir Pehelintsev (fellow sniper) and Nikolai Krasavchenko (Moscow fuel commissioner), they were greeted by thousands at Toronto's Union Station.
The 1976 USSR-issued postage stamp dedicated to PavlichenkoHaving attained the rank of Major, Pavlichenko never returned to combat but became an instructor and trained Soviet snipers until the war's end. In 1943, she was awarded the Gold Star of the Hero of the Soviet Union, and was commemorated on a Soviet postage stamp.
187 kills in 70 days, wow