Couple more items
James--Thx for the vote of confidence.
However, the previous poster asked about the legality of these aftermarket magazines, so I was obliged to answer him, hopefully saving him from creating an illegal rifle.
Your advice on this was correct according to my understanding.
Lawson--Why replace a perfectly good 10 round fixed mag with a 5 round fixed mag? Legal need for hunting? How about rigging a "plug" inside the original mag (as is done with waterfowling shotguns) to simply reduce its capacity if that's what you need?
Took my new 59/66 out to the range today. Shooting steel-cased Russian ammo it was OK. Shot a few "real" rounds, i.e. with brass cases; commercial American stuff. That seemed to go much better. Need to do further testing of course. BTW, her name is Comrade Princess Anastasia. (Yeah, I know, she's Yugoslavian, not Russian, but a. I don't know any Yugoslav names, and b. When a gun tells you her name you don't argue. And her design is Russian.)
NEWS FLASH! NEWS FLASH! Have discovered a way to remove cosmoline from the SKS firing pin channel without dissasembling the bolt. It takes 2 products, brake cleaner and Kroil. Pulled the bolt carrier cover, return spring assembly, the bolt carrier, and the bolt off the gun, that's all. Just worked on the bolt--everything else on the gun seemed to function normally so I left it alone. (Trigger assembly was gooey with cosmo, for example, but it functioned as it should, and I wanted to get out to the range!
) I alternated brake cleaner and Kroil for about 5 applications of each, and at the end the Kroil was running out with next to no brown cosmoline discoloration at all. And, best of all, the firing pin rattled up and down when the bolt was shaken! In the reassembled gun, with the bolt locked open, the firing pin would slide back and forth of its own weight when the gun was tipped perhaps 45° above or below horizontal. Took the SKS out to the range, gave it every opportunity to slam-fire, in 20°F weather, and no problem. Ran at least 40 rounds through, with more in the magazine. ZERO slam-fires! Now, I won't guarantee this down to zero or anything, but when I started cleaning, the firing pin was literally jammed in place by the cosmoline, and only a hard push with a finger would move it in either direction. Plan to leave the whole gun overnight, and examine it in the a.m. to see if there is any change.