It's a classic trade up.
Tight tolerance on all parts means more accuracy. Tight tolerances also means less reliability. Less compatibility.
Loose tolerances on all parts means less accuracy. Loose tolerances are usually implemented for maximum reliability and very easy compatibility.
The SKS isn't inaccurate. It's exactly accurate enough. Accurate to hit a man out to 300 meters in any weather condition imaginable with as little amount of maintenance as possible on the weapon in general,
which is exactly what it was designed to be.
If you want to pinpoint some design features though, I would say, loose fitting stocks, barrels with folding bayonets messing up harmonics and putting odd pressure points on the barrel, it's a semi auto gas operated gun, the sights are crude post and notch, usually people shooting them use standard military surplus ammunition which was mass produced for quantity to be just good enough.
Also the fact that a lot of the ones being shot these days have rough bores.
You have to understand what role the weapon was designed to be used for at the time. It's not a precision marksman rifle, it was never intended to be an MOA or full powered long distance trench warfare rifle. It was designed to shoot, every time you pulled the trigger, in any weather, in any condition and hit a dude out to 300 meters. And that's what she does! And that's why I loves her!
Plus it has an attached folding bayonet!
