I believe you are wrong. Fast Shot, AFAIK, only affects the intrinsic accuracy of a weapon. The random error value introduced to the projectile relative to the barrel of the weapon. Sway is, however, affected by skill level. If you just started a new game, you're probably comparing sway at skill level 30 or 40 to sway on a mature character with guns level 100. Yes, no?
Forgot to mention I have 100 guns skill, over 6 STR, and using a suppressed sniper rifle.
Although I could snipe at max range accurately with my hunting revolver....something is definitely fishy. Perhaps they changed weapon sway for the sniper rifle with the last patch?