Action: semi-automatic, tilting bolt, short stroke piston, gas driven
Barrel Length: 22"
Magazine: 10 round internal, stripper fed
Overall Length: 44"
The M59/66 is actually an updated version of the Yugoslavian M59 SKS. The M59/66 is a unique SKS in the fact that it is the only SKS that has a grenade launcher on it.
The way it works is a button on top of the gas valve is turned off, thus making it possible to raise the grenade sight. The grenade is placed over the end of the muzzle, where it locks onto the rings behind the launcher attachment. A blank is then loaded into the gun, the grenade aimed, and fired. The unusual thing about the M59/66 grenade launcher is that it is NATO spec, while Yugoslavia was actually a communist country.
The M59/66 differs from most other SKS variants in that is doesn't have a chrome lined bore. One theory is that this is mainly (if not totally) the result of the fact that Yugoslavia didn't have any significant deposits of chromium. This theory has not been totally substantiated, and is argued against by many.
The Yugo SKS is a extremely fine piece of machinery, and is insanely fun to shoot. As of the writing of this article, the Yugo SKS can be had for $80-$180 all the way from good to new condition. There is no reason that everyone shouldn't have one. That means you. Go. Go buy now.