Ok, So some people have been talking about why they are not as accurate.

Well as I Am sure you ahev noticed but when you shoot a DRM Or a needle rifle "fast" the reticule gets bigger and there is a less chance you will hit your enemy

Same actually happens with the sniper, so line up your shot and fire in slow controlled burts. Spraying wildly would have a small chance of killing someone anyway... but now that your reticule gets bigger it is even more of a factor