the Soviet Union. Soviet snipers were trained in their skills as marksmen, in using the terrain to hide themselves from the enemy and the ability to work alongside regular forces. This made the Soviet sniper training focus more on "normal" combat situations than those of other nations. Snipers reappeared as important factors on the battlefield from the first campaign of World War II. During Germany's 1940 campaigns, lone, well-hidden French and British snipers were able to halt the German advance for a considerable amount of time. For example, during the pursuit to Dunkirk, British snipers were able to significantly delay the German infantry's advance. This prompted the British once again to increase training of specialized sniper units. Apart from marksmanship, British snipers were trained to blend in with the environment, often by using special camouflage clothing for concealment. However, because the British Army offered sniper training exclusively to officers and non-commissioned officers, the resulting small number of trained snipers in combat units considerably reduced their overall effectiveness. During the Winter War, Finnish snipers took a heavy toll of the invading Red Army. Simo Häyhä is credited with 505 confirmed kills, most with the Finnish version of the iron-sighted bolt-action Mosin–Nagant. One of the best known battles involving snipers, and the battle that made the Germans reinstate their specialized sniper training, was the Battle of Stalingrad. Their defensive position inside a city filled with rubble meant that Soviet snipers were able to inflict significant casualties on the Wehrmacht troops. Because of the nature of fighting in city rubble, snipers were very hard to spot and seriously dented the morale of the German attackers. The best known of these snipers was probably Vasily Zaytsev, featured in the novel War of the Rats and the subsequent film Enemy at the Gates. German Scharfschützen were prepared before the war, equipped with Karabiner 98 and later Gewehr 43 rifles, but there were often not enough of these weapons available, and as such some were armed with captured scoped Mosin–Nagant 1891/30, SVT, Czech Mauser rifles or scoped Gewehr 98 from WW1. The Wehrmacht re-established its sniper training in 1942, drastically increasing the number of snipers per unit with the creation of an additional 31 sniper training companies by 1944. German snipers were at the time the only snipers in the world issued with purpose-manufactured sniping ammunition, known as the 'effect-firing' sS round. The 'effect-firing' sS round