I just purchased one of the Yugoslav M59/66 SKS rifles. The gun is full of cosmoline and from what I've gathered from various translations of the log book that came with it, the rifle has had "around 50" rounds through it.

The gun looks brand new, with no appreciable wear anywhere on the rifle except for a few dings in the stock.

Looking at the face of the bolt, it appears that the opening of the firing pin hole is slightly out of round in one spot where the drill bit obviously wandered during the drilling process. Examining this spot under an intense white LED borelight, this out-of-round "bevel" does not go very deep, and appears to not even have the length of the tapered portion of the firing pin. In other words, it truly is just at the opening to the firing pin hole and it is not that the entire firing pin channel is out of round.

Now, I suppose that if some military armorer in the former Yugoslavia did not see this defect as a potential safety hazard, then perhaps I shouldn't worry about it. I seem to remember, however, reading an M-16 depot repair manual which stated that erosion leading from the bolt face into the firing pin channel is cause to reject the bolt.

Now I know we are not talking about erosion, just a manufacturing flaw, but is this flaw a potential safety hazard? Could it create a drag on the firing pin creating a hazard or potential unreliability situation?

I admit I'm trying to thin out my gun collection a little bit, so I'm going over my guns looking for reasons to reject some, but am I being paranoid about such a tiny flaw?

Will give you an ugly looking fired primer, but as long as the firing pin and the through-hole are straight, shouldn't present a problem. Definitely not a safety problem - maybe a reliability problem down the road with lots of firings.

Can't remember where the gas relief port(s) are for an SKS, although I've owned several of them, Russian and Chinese. If the ruptured primer gas is relieved through the firing pin hole, this could erode the bolt face at the false start and really enlarge the firing pin hole. Someone is going to have to help us here.

Will give you an ugly looking fired primer, but as long as the firing pin and the through-hole are straight, shouldn't present a problem. Definitely not a safety problem - maybe a reliability problem down the road with lots of firings.

Can't remember where the gas relief port(s) are for an SKS, although I've owned several of them, Russian and Chinese. If the ruptured primer gas is relieved through the firing pin hole, this could erode the bolt face at the false start and really enlarge the firing pin hole. Someone is going to have to help us here.

No gas cuts or ports, so if there is a rupture it's got to get out back through the action/bolt. Is a nice large ejector race way mon the left..clearance on both sides of the extractor to the right...and the firing pin channel in the center as choices.

Probably not a problem as you describe it...those mil.spec. sttel cased rounds have some pretty tough primers. If it does proove to be a problem, belive a bolt could be found and fitted, but I'd shoot it (carfully, and with one single round at a time at first) and take a look at the primer'c ondition before hand.

More worrisome would be sticking the firing pin forward by fouling of a bit of blow primer debris.