The M76 also has an adjustable gas system, and is usually in 8mm Mauser, while the SVD/Tiger are commonly in 7.62x54R. Both are very capable cartridges. Many people make the mistake of thinking of these rifles as "sniper" or "precision" rifles, when they are more correctly a designated marksman's rifle. Although often used in the role of a "sniper" rifle, the tactics for the rifle squad using these weapons is to extend the range of the unit from 300 meters or so (AK47/74) out to around 800 meters.
All the countries making these sorts of full sized cartridge case battle rifles (Yugoslavia, Russia, Romania, China, Iraq) know how to build precision rifles, so the use of these rifles is a choice, it is not because they don't know how do build anything with more accuracy.
I had one of the stamped receiver Romanian Romak rifles, and although I sent it off to Krebs custom to have them accurize it as much as possible, without decent 67.62x54R ammo, the best I could get out of it with ball ammo was about 2 MOA...about the same as shooting an M1A with ball ammo.