Probably the original purpose built iteration of what we would consider the Designated Marksman Rifle, the SVD Dragunov was the Sniper Weapon developed out of the WWII Soviet Sniper Doctrine.
The Red Army saw the advantages of an accurate (enough) semi-automatic rifle able to rapidly engage targets and put them out of action much earlier than the NATO Militaries did. Bolt actions were the standard of the west up until GWOT when rifles like the Mk12, Mk11, and M110 finally started popping in to show their utility.
Semi-automatic snipers systems have become the standard for mobile fighting elements while bolt-actions have been pushed into the extreme range category for effective distances beyond 1,000 yards. The .300 WinMag and .338 LapuaMag systems have done well occupying that space.
And be sure to pop over to 9-Hole and jump down that rabbit hole of information for awhile. Its the weekend! Have some fun.