I have re-stocked, to American Size, many, many, of the SKS and have reparied and test fired twice as many. I haven't experienced any slam fires with the SKS.
Using the corrosive ammo from abroad will create a lot of residue in the weapon and I suggest against it. Use of American 7.62X39 ammo is recommended.
I agree with the Russian SKS as apposed to China. It is better made, less tollerance in the action etc. Being exposed to this rifle, and caliber, in South East Asia, it is a good rifle. Here in GA we use them for deer and hog hunting, Small Deer.