The Yugo SKS seems like a well made rifle. I have one. Excellent shooter.
However, know and understand it's weak link in the gas shut-off valve.
That's a feature unque to the Yugo among all the other SKS variants.
The Yugo has a gas-valve behind the front sight. One setting is for
semi-auto fire. The other setting cuts off the gas return to the
gas piston, allowing the gun to also be used as a launching platform
for rifle grenades. When the gas valve goes bad, the return gas leaks
around the valve and doesn't provide enough power to properly cycle
the semi-automatic action.
Go to the Yugoslavian section of SKSBoards to learn more:
sksboards.com/smf/index.php?board=4.0
And from everything I've read, don't waste your time and money on
the aftermarket detatchable magazines. Nothing but trouble.
Your experience (and those of others on the board) may vary, but
I've read too many negative posts to every trust an aftermarket mag
in an SKS.
And -- common to almost all SKS rifles -- make sure that when you clean
yours up, the free-floating firing pin rattles freely in the bolt carrier.
A sticky firing pin in an SKS can quickly turn your semi-auto into an
unintentional, and uncontrolled full-auto until it empties the magazine.
That can obviously be quite dangerous, not to mention winning you a
free trip to Club Fed.